diff --git a/5.6/Dockerfile b/5.6/Dockerfile
index 89f6fe4bd6..fcd72a1245 100644
--- a/5.6/Dockerfile
+++ b/5.6/Dockerfile
@@ -38,9 +38,9 @@ RUN mkdir -p $PHP_INI_DIR/conf.d
 # Enable linker optimization (this sorts the hash buckets to improve cache locality, and is non-default)
 # Adds GNU HASH segments to generated executables (this is used if present, and is much faster than sysv hash; in this configuration, sysv hash is also generated)
 # https://github.com/docker-library/php/issues/272
-ENV CFLAGS="-fstack-protector-strong -fpic -fpie -O2"
-ENV CPPFLAGS="$CFLAGS"
-ENV LDFLAGS="-Wl,-O1 -Wl,--hash-style=both"
+ENV PHP_CFLAGS="-fstack-protector-strong -fpic -fpie -O2"
+ENV PHP_CPPFLAGS="$PHP_CFLAGS"
+ENV PHP_LDFLAGS="-Wl,-O1 -Wl,--hash-style=both -pie"
 
 ENV GPG_KEYS 0BD78B5F97500D450838F95DFE857D9A90D90EC1 6E4F6AB321FDC07F2C332E3AC2BF0BC433CFC8B3
 
@@ -94,6 +94,9 @@ RUN set -xe \
 	" \
 	&& apt-get update && apt-get install -y $buildDeps --no-install-recommends && rm -rf /var/lib/apt/lists/* \
 	\
+	&& export CFLAGS="$PHP_CFLAGS" \
+		CPPFLAGS="$PHP_CPPFLAGS" \
+		LDFLAGS="$PHP_LDFLAGS" \
 	&& docker-php-source extract \
 	&& cd /usr/src/php \
 	&& ./configure \
diff --git a/5.6/alpine/Dockerfile b/5.6/alpine/Dockerfile
index 9a73a79295..ac77397e61 100644
--- a/5.6/alpine/Dockerfile
+++ b/5.6/alpine/Dockerfile
@@ -43,9 +43,9 @@ RUN mkdir -p $PHP_INI_DIR/conf.d
 # Enable linker optimization (this sorts the hash buckets to improve cache locality, and is non-default)
 # Adds GNU HASH segments to generated executables (this is used if present, and is much faster than sysv hash; in this configuration, sysv hash is also generated)
 # https://github.com/docker-library/php/issues/272
-ENV CFLAGS="-fstack-protector-strong -fpic -fpie -O2"
-ENV CPPFLAGS="$CFLAGS"
-ENV LDFLAGS="-Wl,-O1 -Wl,--hash-style=both"
+ENV PHP_CFLAGS="-fstack-protector-strong -fpic -fpie -O2"
+ENV PHP_CPPFLAGS="$PHP_CFLAGS"
+ENV PHP_LDFLAGS="-Wl,-O1 -Wl,--hash-style=both -pie"
 
 ENV GPG_KEYS 0BD78B5F97500D450838F95DFE857D9A90D90EC1 6E4F6AB321FDC07F2C332E3AC2BF0BC433CFC8B3
 
@@ -95,6 +95,9 @@ RUN set -xe \
 		openssl-dev \
 		sqlite-dev \
 	\
+	&& export CFLAGS="$PHP_CFLAGS" \
+		CPPFLAGS="$PHP_CPPFLAGS" \
+		LDFLAGS="$PHP_LDFLAGS" \
 	&& docker-php-source extract \
 	&& cd /usr/src/php \
 	&& ./configure \
diff --git a/5.6/alpine/docker-php-ext-configure b/5.6/alpine/docker-php-ext-configure
index 2a6f8394ea..93d31601c9 100755
--- a/5.6/alpine/docker-php-ext-configure
+++ b/5.6/alpine/docker-php-ext-configure
@@ -1,6 +1,12 @@
 #!/bin/sh
 set -e
 
+# prefer user supplied CFLAGS, but default to our PHP_CFLAGS
+: ${CFLAGS:=$PHP_CFLAGS}
+: ${CPPFLAGS:=$PHP_CPPFLAGS}
+: ${LDFLAGS:=$PHP_LDFLAGS}
+export CFLAGS CPPFLAGS LDFLAGS
+
 srcExists=
 if [ -d /usr/src/php ]; then
 	srcExists=1
diff --git a/5.6/alpine/docker-php-ext-install b/5.6/alpine/docker-php-ext-install
index 79df34e176..c06602302f 100755
--- a/5.6/alpine/docker-php-ext-install
+++ b/5.6/alpine/docker-php-ext-install
@@ -1,6 +1,12 @@
 #!/bin/sh
 set -e
 
+# prefer user supplied CFLAGS, but default to our PHP_CFLAGS
+: ${CFLAGS:=$PHP_CFLAGS}
+: ${CPPFLAGS:=$PHP_CPPFLAGS}
+: ${LDFLAGS:=$PHP_LDFLAGS}
+export CFLAGS CPPFLAGS LDFLAGS
+
 srcExists=
 if [ -d /usr/src/php ]; then
 	srcExists=1
diff --git a/5.6/apache/Dockerfile b/5.6/apache/Dockerfile
index 31d5a50b33..aa82224411 100644
--- a/5.6/apache/Dockerfile
+++ b/5.6/apache/Dockerfile
@@ -94,9 +94,9 @@ ENV PHP_EXTRA_CONFIGURE_ARGS --with-apxs2
 # Enable linker optimization (this sorts the hash buckets to improve cache locality, and is non-default)
 # Adds GNU HASH segments to generated executables (this is used if present, and is much faster than sysv hash; in this configuration, sysv hash is also generated)
 # https://github.com/docker-library/php/issues/272
-ENV CFLAGS="-fstack-protector-strong -fpic -fpie -O2"
-ENV CPPFLAGS="$CFLAGS"
-ENV LDFLAGS="-Wl,-O1 -Wl,--hash-style=both"
+ENV PHP_CFLAGS="-fstack-protector-strong -fpic -fpie -O2"
+ENV PHP_CPPFLAGS="$PHP_CFLAGS"
+ENV PHP_LDFLAGS="-Wl,-O1 -Wl,--hash-style=both -pie"
 
 ENV GPG_KEYS 0BD78B5F97500D450838F95DFE857D9A90D90EC1 6E4F6AB321FDC07F2C332E3AC2BF0BC433CFC8B3
 
@@ -150,6 +150,9 @@ RUN set -xe \
 	" \
 	&& apt-get update && apt-get install -y $buildDeps --no-install-recommends && rm -rf /var/lib/apt/lists/* \
 	\
+	&& export CFLAGS="$PHP_CFLAGS" \
+		CPPFLAGS="$PHP_CPPFLAGS" \
+		LDFLAGS="$PHP_LDFLAGS" \
 	&& docker-php-source extract \
 	&& cd /usr/src/php \
 	&& ./configure \
diff --git a/5.6/apache/docker-php-ext-configure b/5.6/apache/docker-php-ext-configure
index 2a6f8394ea..93d31601c9 100755
--- a/5.6/apache/docker-php-ext-configure
+++ b/5.6/apache/docker-php-ext-configure
@@ -1,6 +1,12 @@
 #!/bin/sh
 set -e
 
+# prefer user supplied CFLAGS, but default to our PHP_CFLAGS
+: ${CFLAGS:=$PHP_CFLAGS}
+: ${CPPFLAGS:=$PHP_CPPFLAGS}
+: ${LDFLAGS:=$PHP_LDFLAGS}
+export CFLAGS CPPFLAGS LDFLAGS
+
 srcExists=
 if [ -d /usr/src/php ]; then
 	srcExists=1
diff --git a/5.6/apache/docker-php-ext-install b/5.6/apache/docker-php-ext-install
index 79df34e176..c06602302f 100755
--- a/5.6/apache/docker-php-ext-install
+++ b/5.6/apache/docker-php-ext-install
@@ -1,6 +1,12 @@
 #!/bin/sh
 set -e
 
+# prefer user supplied CFLAGS, but default to our PHP_CFLAGS
+: ${CFLAGS:=$PHP_CFLAGS}
+: ${CPPFLAGS:=$PHP_CPPFLAGS}
+: ${LDFLAGS:=$PHP_LDFLAGS}
+export CFLAGS CPPFLAGS LDFLAGS
+
 srcExists=
 if [ -d /usr/src/php ]; then
 	srcExists=1
diff --git a/5.6/docker-php-ext-configure b/5.6/docker-php-ext-configure
index 2a6f8394ea..93d31601c9 100755
--- a/5.6/docker-php-ext-configure
+++ b/5.6/docker-php-ext-configure
@@ -1,6 +1,12 @@
 #!/bin/sh
 set -e
 
+# prefer user supplied CFLAGS, but default to our PHP_CFLAGS
+: ${CFLAGS:=$PHP_CFLAGS}
+: ${CPPFLAGS:=$PHP_CPPFLAGS}
+: ${LDFLAGS:=$PHP_LDFLAGS}
+export CFLAGS CPPFLAGS LDFLAGS
+
 srcExists=
 if [ -d /usr/src/php ]; then
 	srcExists=1
diff --git a/5.6/docker-php-ext-install b/5.6/docker-php-ext-install
index 79df34e176..c06602302f 100755
--- a/5.6/docker-php-ext-install
+++ b/5.6/docker-php-ext-install
@@ -1,6 +1,12 @@
 #!/bin/sh
 set -e
 
+# prefer user supplied CFLAGS, but default to our PHP_CFLAGS
+: ${CFLAGS:=$PHP_CFLAGS}
+: ${CPPFLAGS:=$PHP_CPPFLAGS}
+: ${LDFLAGS:=$PHP_LDFLAGS}
+export CFLAGS CPPFLAGS LDFLAGS
+
 srcExists=
 if [ -d /usr/src/php ]; then
 	srcExists=1
diff --git a/5.6/fpm/Dockerfile b/5.6/fpm/Dockerfile
index d7536790e8..521fdba860 100644
--- a/5.6/fpm/Dockerfile
+++ b/5.6/fpm/Dockerfile
@@ -39,9 +39,9 @@ ENV PHP_EXTRA_CONFIGURE_ARGS --enable-fpm --with-fpm-user=www-data --with-fpm-gr
 # Enable linker optimization (this sorts the hash buckets to improve cache locality, and is non-default)
 # Adds GNU HASH segments to generated executables (this is used if present, and is much faster than sysv hash; in this configuration, sysv hash is also generated)
 # https://github.com/docker-library/php/issues/272
-ENV CFLAGS="-fstack-protector-strong -fpic -fpie -O2"
-ENV CPPFLAGS="$CFLAGS"
-ENV LDFLAGS="-Wl,-O1 -Wl,--hash-style=both"
+ENV PHP_CFLAGS="-fstack-protector-strong -fpic -fpie -O2"
+ENV PHP_CPPFLAGS="$PHP_CFLAGS"
+ENV PHP_LDFLAGS="-Wl,-O1 -Wl,--hash-style=both -pie"
 
 ENV GPG_KEYS 0BD78B5F97500D450838F95DFE857D9A90D90EC1 6E4F6AB321FDC07F2C332E3AC2BF0BC433CFC8B3
 
@@ -95,6 +95,9 @@ RUN set -xe \
 	" \
 	&& apt-get update && apt-get install -y $buildDeps --no-install-recommends && rm -rf /var/lib/apt/lists/* \
 	\
+	&& export CFLAGS="$PHP_CFLAGS" \
+		CPPFLAGS="$PHP_CPPFLAGS" \
+		LDFLAGS="$PHP_LDFLAGS" \
 	&& docker-php-source extract \
 	&& cd /usr/src/php \
 	&& ./configure \
diff --git a/5.6/fpm/alpine/Dockerfile b/5.6/fpm/alpine/Dockerfile
index ab9a90f4a1..afdd7d28ec 100644
--- a/5.6/fpm/alpine/Dockerfile
+++ b/5.6/fpm/alpine/Dockerfile
@@ -44,9 +44,9 @@ ENV PHP_EXTRA_CONFIGURE_ARGS --enable-fpm --with-fpm-user=www-data --with-fpm-gr
 # Enable linker optimization (this sorts the hash buckets to improve cache locality, and is non-default)
 # Adds GNU HASH segments to generated executables (this is used if present, and is much faster than sysv hash; in this configuration, sysv hash is also generated)
 # https://github.com/docker-library/php/issues/272
-ENV CFLAGS="-fstack-protector-strong -fpic -fpie -O2"
-ENV CPPFLAGS="$CFLAGS"
-ENV LDFLAGS="-Wl,-O1 -Wl,--hash-style=both"
+ENV PHP_CFLAGS="-fstack-protector-strong -fpic -fpie -O2"
+ENV PHP_CPPFLAGS="$PHP_CFLAGS"
+ENV PHP_LDFLAGS="-Wl,-O1 -Wl,--hash-style=both -pie"
 
 ENV GPG_KEYS 0BD78B5F97500D450838F95DFE857D9A90D90EC1 6E4F6AB321FDC07F2C332E3AC2BF0BC433CFC8B3
 
@@ -96,6 +96,9 @@ RUN set -xe \
 		openssl-dev \
 		sqlite-dev \
 	\
+	&& export CFLAGS="$PHP_CFLAGS" \
+		CPPFLAGS="$PHP_CPPFLAGS" \
+		LDFLAGS="$PHP_LDFLAGS" \
 	&& docker-php-source extract \
 	&& cd /usr/src/php \
 	&& ./configure \
diff --git a/5.6/fpm/alpine/docker-php-ext-configure b/5.6/fpm/alpine/docker-php-ext-configure
index 2a6f8394ea..93d31601c9 100755
--- a/5.6/fpm/alpine/docker-php-ext-configure
+++ b/5.6/fpm/alpine/docker-php-ext-configure
@@ -1,6 +1,12 @@
 #!/bin/sh
 set -e
 
+# prefer user supplied CFLAGS, but default to our PHP_CFLAGS
+: ${CFLAGS:=$PHP_CFLAGS}
+: ${CPPFLAGS:=$PHP_CPPFLAGS}
+: ${LDFLAGS:=$PHP_LDFLAGS}
+export CFLAGS CPPFLAGS LDFLAGS
+
 srcExists=
 if [ -d /usr/src/php ]; then
 	srcExists=1
diff --git a/5.6/fpm/alpine/docker-php-ext-install b/5.6/fpm/alpine/docker-php-ext-install
index 79df34e176..c06602302f 100755
--- a/5.6/fpm/alpine/docker-php-ext-install
+++ b/5.6/fpm/alpine/docker-php-ext-install
@@ -1,6 +1,12 @@
 #!/bin/sh
 set -e
 
+# prefer user supplied CFLAGS, but default to our PHP_CFLAGS
+: ${CFLAGS:=$PHP_CFLAGS}
+: ${CPPFLAGS:=$PHP_CPPFLAGS}
+: ${LDFLAGS:=$PHP_LDFLAGS}
+export CFLAGS CPPFLAGS LDFLAGS
+
 srcExists=
 if [ -d /usr/src/php ]; then
 	srcExists=1
diff --git a/5.6/fpm/docker-php-ext-configure b/5.6/fpm/docker-php-ext-configure
index 2a6f8394ea..93d31601c9 100755
--- a/5.6/fpm/docker-php-ext-configure
+++ b/5.6/fpm/docker-php-ext-configure
@@ -1,6 +1,12 @@
 #!/bin/sh
 set -e
 
+# prefer user supplied CFLAGS, but default to our PHP_CFLAGS
+: ${CFLAGS:=$PHP_CFLAGS}
+: ${CPPFLAGS:=$PHP_CPPFLAGS}
+: ${LDFLAGS:=$PHP_LDFLAGS}
+export CFLAGS CPPFLAGS LDFLAGS
+
 srcExists=
 if [ -d /usr/src/php ]; then
 	srcExists=1
diff --git a/5.6/fpm/docker-php-ext-install b/5.6/fpm/docker-php-ext-install
index 79df34e176..c06602302f 100755
--- a/5.6/fpm/docker-php-ext-install
+++ b/5.6/fpm/docker-php-ext-install
@@ -1,6 +1,12 @@
 #!/bin/sh
 set -e
 
+# prefer user supplied CFLAGS, but default to our PHP_CFLAGS
+: ${CFLAGS:=$PHP_CFLAGS}
+: ${CPPFLAGS:=$PHP_CPPFLAGS}
+: ${LDFLAGS:=$PHP_LDFLAGS}
+export CFLAGS CPPFLAGS LDFLAGS
+
 srcExists=
 if [ -d /usr/src/php ]; then
 	srcExists=1
diff --git a/5.6/zts/Dockerfile b/5.6/zts/Dockerfile
index 4895987b50..63f17f9f1d 100644
--- a/5.6/zts/Dockerfile
+++ b/5.6/zts/Dockerfile
@@ -39,9 +39,9 @@ ENV PHP_EXTRA_CONFIGURE_ARGS --enable-maintainer-zts
 # Enable linker optimization (this sorts the hash buckets to improve cache locality, and is non-default)
 # Adds GNU HASH segments to generated executables (this is used if present, and is much faster than sysv hash; in this configuration, sysv hash is also generated)
 # https://github.com/docker-library/php/issues/272
-ENV CFLAGS="-fstack-protector-strong -fpic -fpie -O2"
-ENV CPPFLAGS="$CFLAGS"
-ENV LDFLAGS="-Wl,-O1 -Wl,--hash-style=both"
+ENV PHP_CFLAGS="-fstack-protector-strong -fpic -fpie -O2"
+ENV PHP_CPPFLAGS="$PHP_CFLAGS"
+ENV PHP_LDFLAGS="-Wl,-O1 -Wl,--hash-style=both -pie"
 
 ENV GPG_KEYS 0BD78B5F97500D450838F95DFE857D9A90D90EC1 6E4F6AB321FDC07F2C332E3AC2BF0BC433CFC8B3
 
@@ -95,6 +95,9 @@ RUN set -xe \
 	" \
 	&& apt-get update && apt-get install -y $buildDeps --no-install-recommends && rm -rf /var/lib/apt/lists/* \
 	\
+	&& export CFLAGS="$PHP_CFLAGS" \
+		CPPFLAGS="$PHP_CPPFLAGS" \
+		LDFLAGS="$PHP_LDFLAGS" \
 	&& docker-php-source extract \
 	&& cd /usr/src/php \
 	&& ./configure \
diff --git a/5.6/zts/alpine/Dockerfile b/5.6/zts/alpine/Dockerfile
index 29bcf7cfe2..688e5c7563 100644
--- a/5.6/zts/alpine/Dockerfile
+++ b/5.6/zts/alpine/Dockerfile
@@ -44,9 +44,9 @@ ENV PHP_EXTRA_CONFIGURE_ARGS --enable-maintainer-zts
 # Enable linker optimization (this sorts the hash buckets to improve cache locality, and is non-default)
 # Adds GNU HASH segments to generated executables (this is used if present, and is much faster than sysv hash; in this configuration, sysv hash is also generated)
 # https://github.com/docker-library/php/issues/272
-ENV CFLAGS="-fstack-protector-strong -fpic -fpie -O2"
-ENV CPPFLAGS="$CFLAGS"
-ENV LDFLAGS="-Wl,-O1 -Wl,--hash-style=both"
+ENV PHP_CFLAGS="-fstack-protector-strong -fpic -fpie -O2"
+ENV PHP_CPPFLAGS="$PHP_CFLAGS"
+ENV PHP_LDFLAGS="-Wl,-O1 -Wl,--hash-style=both -pie"
 
 ENV GPG_KEYS 0BD78B5F97500D450838F95DFE857D9A90D90EC1 6E4F6AB321FDC07F2C332E3AC2BF0BC433CFC8B3
 
@@ -96,6 +96,9 @@ RUN set -xe \
 		openssl-dev \
 		sqlite-dev \
 	\
+	&& export CFLAGS="$PHP_CFLAGS" \
+		CPPFLAGS="$PHP_CPPFLAGS" \
+		LDFLAGS="$PHP_LDFLAGS" \
 	&& docker-php-source extract \
 	&& cd /usr/src/php \
 	&& ./configure \
diff --git a/5.6/zts/alpine/docker-php-ext-configure b/5.6/zts/alpine/docker-php-ext-configure
index 2a6f8394ea..93d31601c9 100755
--- a/5.6/zts/alpine/docker-php-ext-configure
+++ b/5.6/zts/alpine/docker-php-ext-configure
@@ -1,6 +1,12 @@
 #!/bin/sh
 set -e
 
+# prefer user supplied CFLAGS, but default to our PHP_CFLAGS
+: ${CFLAGS:=$PHP_CFLAGS}
+: ${CPPFLAGS:=$PHP_CPPFLAGS}
+: ${LDFLAGS:=$PHP_LDFLAGS}
+export CFLAGS CPPFLAGS LDFLAGS
+
 srcExists=
 if [ -d /usr/src/php ]; then
 	srcExists=1
diff --git a/5.6/zts/alpine/docker-php-ext-install b/5.6/zts/alpine/docker-php-ext-install
index 79df34e176..c06602302f 100755
--- a/5.6/zts/alpine/docker-php-ext-install
+++ b/5.6/zts/alpine/docker-php-ext-install
@@ -1,6 +1,12 @@
 #!/bin/sh
 set -e
 
+# prefer user supplied CFLAGS, but default to our PHP_CFLAGS
+: ${CFLAGS:=$PHP_CFLAGS}
+: ${CPPFLAGS:=$PHP_CPPFLAGS}
+: ${LDFLAGS:=$PHP_LDFLAGS}
+export CFLAGS CPPFLAGS LDFLAGS
+
 srcExists=
 if [ -d /usr/src/php ]; then
 	srcExists=1
diff --git a/5.6/zts/docker-php-ext-configure b/5.6/zts/docker-php-ext-configure
index 2a6f8394ea..93d31601c9 100755
--- a/5.6/zts/docker-php-ext-configure
+++ b/5.6/zts/docker-php-ext-configure
@@ -1,6 +1,12 @@
 #!/bin/sh
 set -e
 
+# prefer user supplied CFLAGS, but default to our PHP_CFLAGS
+: ${CFLAGS:=$PHP_CFLAGS}
+: ${CPPFLAGS:=$PHP_CPPFLAGS}
+: ${LDFLAGS:=$PHP_LDFLAGS}
+export CFLAGS CPPFLAGS LDFLAGS
+
 srcExists=
 if [ -d /usr/src/php ]; then
 	srcExists=1
diff --git a/5.6/zts/docker-php-ext-install b/5.6/zts/docker-php-ext-install
index 79df34e176..c06602302f 100755
--- a/5.6/zts/docker-php-ext-install
+++ b/5.6/zts/docker-php-ext-install
@@ -1,6 +1,12 @@
 #!/bin/sh
 set -e
 
+# prefer user supplied CFLAGS, but default to our PHP_CFLAGS
+: ${CFLAGS:=$PHP_CFLAGS}
+: ${CPPFLAGS:=$PHP_CPPFLAGS}
+: ${LDFLAGS:=$PHP_LDFLAGS}
+export CFLAGS CPPFLAGS LDFLAGS
+
 srcExists=
 if [ -d /usr/src/php ]; then
 	srcExists=1
diff --git a/7.0/Dockerfile b/7.0/Dockerfile
index 6ce44750d9..71b0e2bd8c 100644
--- a/7.0/Dockerfile
+++ b/7.0/Dockerfile
@@ -38,9 +38,9 @@ RUN mkdir -p $PHP_INI_DIR/conf.d
 # Enable linker optimization (this sorts the hash buckets to improve cache locality, and is non-default)
 # Adds GNU HASH segments to generated executables (this is used if present, and is much faster than sysv hash; in this configuration, sysv hash is also generated)
 # https://github.com/docker-library/php/issues/272
-ENV CFLAGS="-fstack-protector-strong -fpic -fpie -O2"
-ENV CPPFLAGS="$CFLAGS"
-ENV LDFLAGS="-Wl,-O1 -Wl,--hash-style=both"
+ENV PHP_CFLAGS="-fstack-protector-strong -fpic -fpie -O2"
+ENV PHP_CPPFLAGS="$PHP_CFLAGS"
+ENV PHP_LDFLAGS="-Wl,-O1 -Wl,--hash-style=both -pie"
 
 ENV GPG_KEYS 1A4E8B7277C42E53DBA9C7B9BCAA30EA9C0D5763
 
@@ -94,6 +94,9 @@ RUN set -xe \
 	" \
 	&& apt-get update && apt-get install -y $buildDeps --no-install-recommends && rm -rf /var/lib/apt/lists/* \
 	\
+	&& export CFLAGS="$PHP_CFLAGS" \
+		CPPFLAGS="$PHP_CPPFLAGS" \
+		LDFLAGS="$PHP_LDFLAGS" \
 	&& docker-php-source extract \
 	&& cd /usr/src/php \
 	&& ./configure \
diff --git a/7.0/alpine/Dockerfile b/7.0/alpine/Dockerfile
index 0fea38bc53..b42ea75040 100644
--- a/7.0/alpine/Dockerfile
+++ b/7.0/alpine/Dockerfile
@@ -43,9 +43,9 @@ RUN mkdir -p $PHP_INI_DIR/conf.d
 # Enable linker optimization (this sorts the hash buckets to improve cache locality, and is non-default)
 # Adds GNU HASH segments to generated executables (this is used if present, and is much faster than sysv hash; in this configuration, sysv hash is also generated)
 # https://github.com/docker-library/php/issues/272
-ENV CFLAGS="-fstack-protector-strong -fpic -fpie -O2"
-ENV CPPFLAGS="$CFLAGS"
-ENV LDFLAGS="-Wl,-O1 -Wl,--hash-style=both"
+ENV PHP_CFLAGS="-fstack-protector-strong -fpic -fpie -O2"
+ENV PHP_CPPFLAGS="$PHP_CFLAGS"
+ENV PHP_LDFLAGS="-Wl,-O1 -Wl,--hash-style=both -pie"
 
 ENV GPG_KEYS 1A4E8B7277C42E53DBA9C7B9BCAA30EA9C0D5763
 
@@ -95,6 +95,9 @@ RUN set -xe \
 		openssl-dev \
 		sqlite-dev \
 	\
+	&& export CFLAGS="$PHP_CFLAGS" \
+		CPPFLAGS="$PHP_CPPFLAGS" \
+		LDFLAGS="$PHP_LDFLAGS" \
 	&& docker-php-source extract \
 	&& cd /usr/src/php \
 	&& ./configure \
diff --git a/7.0/alpine/docker-php-ext-configure b/7.0/alpine/docker-php-ext-configure
index 2a6f8394ea..93d31601c9 100755
--- a/7.0/alpine/docker-php-ext-configure
+++ b/7.0/alpine/docker-php-ext-configure
@@ -1,6 +1,12 @@
 #!/bin/sh
 set -e
 
+# prefer user supplied CFLAGS, but default to our PHP_CFLAGS
+: ${CFLAGS:=$PHP_CFLAGS}
+: ${CPPFLAGS:=$PHP_CPPFLAGS}
+: ${LDFLAGS:=$PHP_LDFLAGS}
+export CFLAGS CPPFLAGS LDFLAGS
+
 srcExists=
 if [ -d /usr/src/php ]; then
 	srcExists=1
diff --git a/7.0/alpine/docker-php-ext-install b/7.0/alpine/docker-php-ext-install
index 79df34e176..c06602302f 100755
--- a/7.0/alpine/docker-php-ext-install
+++ b/7.0/alpine/docker-php-ext-install
@@ -1,6 +1,12 @@
 #!/bin/sh
 set -e
 
+# prefer user supplied CFLAGS, but default to our PHP_CFLAGS
+: ${CFLAGS:=$PHP_CFLAGS}
+: ${CPPFLAGS:=$PHP_CPPFLAGS}
+: ${LDFLAGS:=$PHP_LDFLAGS}
+export CFLAGS CPPFLAGS LDFLAGS
+
 srcExists=
 if [ -d /usr/src/php ]; then
 	srcExists=1
diff --git a/7.0/apache/Dockerfile b/7.0/apache/Dockerfile
index 18a7319fd0..5a7cbdfa6a 100644
--- a/7.0/apache/Dockerfile
+++ b/7.0/apache/Dockerfile
@@ -94,9 +94,9 @@ ENV PHP_EXTRA_CONFIGURE_ARGS --with-apxs2
 # Enable linker optimization (this sorts the hash buckets to improve cache locality, and is non-default)
 # Adds GNU HASH segments to generated executables (this is used if present, and is much faster than sysv hash; in this configuration, sysv hash is also generated)
 # https://github.com/docker-library/php/issues/272
-ENV CFLAGS="-fstack-protector-strong -fpic -fpie -O2"
-ENV CPPFLAGS="$CFLAGS"
-ENV LDFLAGS="-Wl,-O1 -Wl,--hash-style=both"
+ENV PHP_CFLAGS="-fstack-protector-strong -fpic -fpie -O2"
+ENV PHP_CPPFLAGS="$PHP_CFLAGS"
+ENV PHP_LDFLAGS="-Wl,-O1 -Wl,--hash-style=both -pie"
 
 ENV GPG_KEYS 1A4E8B7277C42E53DBA9C7B9BCAA30EA9C0D5763
 
@@ -150,6 +150,9 @@ RUN set -xe \
 	" \
 	&& apt-get update && apt-get install -y $buildDeps --no-install-recommends && rm -rf /var/lib/apt/lists/* \
 	\
+	&& export CFLAGS="$PHP_CFLAGS" \
+		CPPFLAGS="$PHP_CPPFLAGS" \
+		LDFLAGS="$PHP_LDFLAGS" \
 	&& docker-php-source extract \
 	&& cd /usr/src/php \
 	&& ./configure \
diff --git a/7.0/apache/docker-php-ext-configure b/7.0/apache/docker-php-ext-configure
index 2a6f8394ea..93d31601c9 100755
--- a/7.0/apache/docker-php-ext-configure
+++ b/7.0/apache/docker-php-ext-configure
@@ -1,6 +1,12 @@
 #!/bin/sh
 set -e
 
+# prefer user supplied CFLAGS, but default to our PHP_CFLAGS
+: ${CFLAGS:=$PHP_CFLAGS}
+: ${CPPFLAGS:=$PHP_CPPFLAGS}
+: ${LDFLAGS:=$PHP_LDFLAGS}
+export CFLAGS CPPFLAGS LDFLAGS
+
 srcExists=
 if [ -d /usr/src/php ]; then
 	srcExists=1
diff --git a/7.0/apache/docker-php-ext-install b/7.0/apache/docker-php-ext-install
index 79df34e176..c06602302f 100755
--- a/7.0/apache/docker-php-ext-install
+++ b/7.0/apache/docker-php-ext-install
@@ -1,6 +1,12 @@
 #!/bin/sh
 set -e
 
+# prefer user supplied CFLAGS, but default to our PHP_CFLAGS
+: ${CFLAGS:=$PHP_CFLAGS}
+: ${CPPFLAGS:=$PHP_CPPFLAGS}
+: ${LDFLAGS:=$PHP_LDFLAGS}
+export CFLAGS CPPFLAGS LDFLAGS
+
 srcExists=
 if [ -d /usr/src/php ]; then
 	srcExists=1
diff --git a/7.0/docker-php-ext-configure b/7.0/docker-php-ext-configure
index 2a6f8394ea..93d31601c9 100755
--- a/7.0/docker-php-ext-configure
+++ b/7.0/docker-php-ext-configure
@@ -1,6 +1,12 @@
 #!/bin/sh
 set -e
 
+# prefer user supplied CFLAGS, but default to our PHP_CFLAGS
+: ${CFLAGS:=$PHP_CFLAGS}
+: ${CPPFLAGS:=$PHP_CPPFLAGS}
+: ${LDFLAGS:=$PHP_LDFLAGS}
+export CFLAGS CPPFLAGS LDFLAGS
+
 srcExists=
 if [ -d /usr/src/php ]; then
 	srcExists=1
diff --git a/7.0/docker-php-ext-install b/7.0/docker-php-ext-install
index 79df34e176..c06602302f 100755
--- a/7.0/docker-php-ext-install
+++ b/7.0/docker-php-ext-install
@@ -1,6 +1,12 @@
 #!/bin/sh
 set -e
 
+# prefer user supplied CFLAGS, but default to our PHP_CFLAGS
+: ${CFLAGS:=$PHP_CFLAGS}
+: ${CPPFLAGS:=$PHP_CPPFLAGS}
+: ${LDFLAGS:=$PHP_LDFLAGS}
+export CFLAGS CPPFLAGS LDFLAGS
+
 srcExists=
 if [ -d /usr/src/php ]; then
 	srcExists=1
diff --git a/7.0/fpm/Dockerfile b/7.0/fpm/Dockerfile
index f01de3c470..774be771ba 100644
--- a/7.0/fpm/Dockerfile
+++ b/7.0/fpm/Dockerfile
@@ -39,9 +39,9 @@ ENV PHP_EXTRA_CONFIGURE_ARGS --enable-fpm --with-fpm-user=www-data --with-fpm-gr
 # Enable linker optimization (this sorts the hash buckets to improve cache locality, and is non-default)
 # Adds GNU HASH segments to generated executables (this is used if present, and is much faster than sysv hash; in this configuration, sysv hash is also generated)
 # https://github.com/docker-library/php/issues/272
-ENV CFLAGS="-fstack-protector-strong -fpic -fpie -O2"
-ENV CPPFLAGS="$CFLAGS"
-ENV LDFLAGS="-Wl,-O1 -Wl,--hash-style=both"
+ENV PHP_CFLAGS="-fstack-protector-strong -fpic -fpie -O2"
+ENV PHP_CPPFLAGS="$PHP_CFLAGS"
+ENV PHP_LDFLAGS="-Wl,-O1 -Wl,--hash-style=both -pie"
 
 ENV GPG_KEYS 1A4E8B7277C42E53DBA9C7B9BCAA30EA9C0D5763
 
@@ -95,6 +95,9 @@ RUN set -xe \
 	" \
 	&& apt-get update && apt-get install -y $buildDeps --no-install-recommends && rm -rf /var/lib/apt/lists/* \
 	\
+	&& export CFLAGS="$PHP_CFLAGS" \
+		CPPFLAGS="$PHP_CPPFLAGS" \
+		LDFLAGS="$PHP_LDFLAGS" \
 	&& docker-php-source extract \
 	&& cd /usr/src/php \
 	&& ./configure \
diff --git a/7.0/fpm/alpine/Dockerfile b/7.0/fpm/alpine/Dockerfile
index fecf60bb02..f77dfd614e 100644
--- a/7.0/fpm/alpine/Dockerfile
+++ b/7.0/fpm/alpine/Dockerfile
@@ -44,9 +44,9 @@ ENV PHP_EXTRA_CONFIGURE_ARGS --enable-fpm --with-fpm-user=www-data --with-fpm-gr
 # Enable linker optimization (this sorts the hash buckets to improve cache locality, and is non-default)
 # Adds GNU HASH segments to generated executables (this is used if present, and is much faster than sysv hash; in this configuration, sysv hash is also generated)
 # https://github.com/docker-library/php/issues/272
-ENV CFLAGS="-fstack-protector-strong -fpic -fpie -O2"
-ENV CPPFLAGS="$CFLAGS"
-ENV LDFLAGS="-Wl,-O1 -Wl,--hash-style=both"
+ENV PHP_CFLAGS="-fstack-protector-strong -fpic -fpie -O2"
+ENV PHP_CPPFLAGS="$PHP_CFLAGS"
+ENV PHP_LDFLAGS="-Wl,-O1 -Wl,--hash-style=both -pie"
 
 ENV GPG_KEYS 1A4E8B7277C42E53DBA9C7B9BCAA30EA9C0D5763
 
@@ -96,6 +96,9 @@ RUN set -xe \
 		openssl-dev \
 		sqlite-dev \
 	\
+	&& export CFLAGS="$PHP_CFLAGS" \
+		CPPFLAGS="$PHP_CPPFLAGS" \
+		LDFLAGS="$PHP_LDFLAGS" \
 	&& docker-php-source extract \
 	&& cd /usr/src/php \
 	&& ./configure \
diff --git a/7.0/fpm/alpine/docker-php-ext-configure b/7.0/fpm/alpine/docker-php-ext-configure
index 2a6f8394ea..93d31601c9 100755
--- a/7.0/fpm/alpine/docker-php-ext-configure
+++ b/7.0/fpm/alpine/docker-php-ext-configure
@@ -1,6 +1,12 @@
 #!/bin/sh
 set -e
 
+# prefer user supplied CFLAGS, but default to our PHP_CFLAGS
+: ${CFLAGS:=$PHP_CFLAGS}
+: ${CPPFLAGS:=$PHP_CPPFLAGS}
+: ${LDFLAGS:=$PHP_LDFLAGS}
+export CFLAGS CPPFLAGS LDFLAGS
+
 srcExists=
 if [ -d /usr/src/php ]; then
 	srcExists=1
diff --git a/7.0/fpm/alpine/docker-php-ext-install b/7.0/fpm/alpine/docker-php-ext-install
index 79df34e176..c06602302f 100755
--- a/7.0/fpm/alpine/docker-php-ext-install
+++ b/7.0/fpm/alpine/docker-php-ext-install
@@ -1,6 +1,12 @@
 #!/bin/sh
 set -e
 
+# prefer user supplied CFLAGS, but default to our PHP_CFLAGS
+: ${CFLAGS:=$PHP_CFLAGS}
+: ${CPPFLAGS:=$PHP_CPPFLAGS}
+: ${LDFLAGS:=$PHP_LDFLAGS}
+export CFLAGS CPPFLAGS LDFLAGS
+
 srcExists=
 if [ -d /usr/src/php ]; then
 	srcExists=1
diff --git a/7.0/fpm/docker-php-ext-configure b/7.0/fpm/docker-php-ext-configure
index 2a6f8394ea..93d31601c9 100755
--- a/7.0/fpm/docker-php-ext-configure
+++ b/7.0/fpm/docker-php-ext-configure
@@ -1,6 +1,12 @@
 #!/bin/sh
 set -e
 
+# prefer user supplied CFLAGS, but default to our PHP_CFLAGS
+: ${CFLAGS:=$PHP_CFLAGS}
+: ${CPPFLAGS:=$PHP_CPPFLAGS}
+: ${LDFLAGS:=$PHP_LDFLAGS}
+export CFLAGS CPPFLAGS LDFLAGS
+
 srcExists=
 if [ -d /usr/src/php ]; then
 	srcExists=1
diff --git a/7.0/fpm/docker-php-ext-install b/7.0/fpm/docker-php-ext-install
index 79df34e176..c06602302f 100755
--- a/7.0/fpm/docker-php-ext-install
+++ b/7.0/fpm/docker-php-ext-install
@@ -1,6 +1,12 @@
 #!/bin/sh
 set -e
 
+# prefer user supplied CFLAGS, but default to our PHP_CFLAGS
+: ${CFLAGS:=$PHP_CFLAGS}
+: ${CPPFLAGS:=$PHP_CPPFLAGS}
+: ${LDFLAGS:=$PHP_LDFLAGS}
+export CFLAGS CPPFLAGS LDFLAGS
+
 srcExists=
 if [ -d /usr/src/php ]; then
 	srcExists=1
diff --git a/7.0/zts/Dockerfile b/7.0/zts/Dockerfile
index 68c1b2ac98..8214805623 100644
--- a/7.0/zts/Dockerfile
+++ b/7.0/zts/Dockerfile
@@ -39,9 +39,9 @@ ENV PHP_EXTRA_CONFIGURE_ARGS --enable-maintainer-zts
 # Enable linker optimization (this sorts the hash buckets to improve cache locality, and is non-default)
 # Adds GNU HASH segments to generated executables (this is used if present, and is much faster than sysv hash; in this configuration, sysv hash is also generated)
 # https://github.com/docker-library/php/issues/272
-ENV CFLAGS="-fstack-protector-strong -fpic -fpie -O2"
-ENV CPPFLAGS="$CFLAGS"
-ENV LDFLAGS="-Wl,-O1 -Wl,--hash-style=both"
+ENV PHP_CFLAGS="-fstack-protector-strong -fpic -fpie -O2"
+ENV PHP_CPPFLAGS="$PHP_CFLAGS"
+ENV PHP_LDFLAGS="-Wl,-O1 -Wl,--hash-style=both -pie"
 
 ENV GPG_KEYS 1A4E8B7277C42E53DBA9C7B9BCAA30EA9C0D5763
 
@@ -95,6 +95,9 @@ RUN set -xe \
 	" \
 	&& apt-get update && apt-get install -y $buildDeps --no-install-recommends && rm -rf /var/lib/apt/lists/* \
 	\
+	&& export CFLAGS="$PHP_CFLAGS" \
+		CPPFLAGS="$PHP_CPPFLAGS" \
+		LDFLAGS="$PHP_LDFLAGS" \
 	&& docker-php-source extract \
 	&& cd /usr/src/php \
 	&& ./configure \
diff --git a/7.0/zts/alpine/Dockerfile b/7.0/zts/alpine/Dockerfile
index 2872392e33..3238639f6d 100644
--- a/7.0/zts/alpine/Dockerfile
+++ b/7.0/zts/alpine/Dockerfile
@@ -44,9 +44,9 @@ ENV PHP_EXTRA_CONFIGURE_ARGS --enable-maintainer-zts
 # Enable linker optimization (this sorts the hash buckets to improve cache locality, and is non-default)
 # Adds GNU HASH segments to generated executables (this is used if present, and is much faster than sysv hash; in this configuration, sysv hash is also generated)
 # https://github.com/docker-library/php/issues/272
-ENV CFLAGS="-fstack-protector-strong -fpic -fpie -O2"
-ENV CPPFLAGS="$CFLAGS"
-ENV LDFLAGS="-Wl,-O1 -Wl,--hash-style=both"
+ENV PHP_CFLAGS="-fstack-protector-strong -fpic -fpie -O2"
+ENV PHP_CPPFLAGS="$PHP_CFLAGS"
+ENV PHP_LDFLAGS="-Wl,-O1 -Wl,--hash-style=both -pie"
 
 ENV GPG_KEYS 1A4E8B7277C42E53DBA9C7B9BCAA30EA9C0D5763
 
@@ -96,6 +96,9 @@ RUN set -xe \
 		openssl-dev \
 		sqlite-dev \
 	\
+	&& export CFLAGS="$PHP_CFLAGS" \
+		CPPFLAGS="$PHP_CPPFLAGS" \
+		LDFLAGS="$PHP_LDFLAGS" \
 	&& docker-php-source extract \
 	&& cd /usr/src/php \
 	&& ./configure \
diff --git a/7.0/zts/alpine/docker-php-ext-configure b/7.0/zts/alpine/docker-php-ext-configure
index 2a6f8394ea..93d31601c9 100755
--- a/7.0/zts/alpine/docker-php-ext-configure
+++ b/7.0/zts/alpine/docker-php-ext-configure
@@ -1,6 +1,12 @@
 #!/bin/sh
 set -e
 
+# prefer user supplied CFLAGS, but default to our PHP_CFLAGS
+: ${CFLAGS:=$PHP_CFLAGS}
+: ${CPPFLAGS:=$PHP_CPPFLAGS}
+: ${LDFLAGS:=$PHP_LDFLAGS}
+export CFLAGS CPPFLAGS LDFLAGS
+
 srcExists=
 if [ -d /usr/src/php ]; then
 	srcExists=1
diff --git a/7.0/zts/alpine/docker-php-ext-install b/7.0/zts/alpine/docker-php-ext-install
index 79df34e176..c06602302f 100755
--- a/7.0/zts/alpine/docker-php-ext-install
+++ b/7.0/zts/alpine/docker-php-ext-install
@@ -1,6 +1,12 @@
 #!/bin/sh
 set -e
 
+# prefer user supplied CFLAGS, but default to our PHP_CFLAGS
+: ${CFLAGS:=$PHP_CFLAGS}
+: ${CPPFLAGS:=$PHP_CPPFLAGS}
+: ${LDFLAGS:=$PHP_LDFLAGS}
+export CFLAGS CPPFLAGS LDFLAGS
+
 srcExists=
 if [ -d /usr/src/php ]; then
 	srcExists=1
diff --git a/7.0/zts/docker-php-ext-configure b/7.0/zts/docker-php-ext-configure
index 2a6f8394ea..93d31601c9 100755
--- a/7.0/zts/docker-php-ext-configure
+++ b/7.0/zts/docker-php-ext-configure
@@ -1,6 +1,12 @@
 #!/bin/sh
 set -e
 
+# prefer user supplied CFLAGS, but default to our PHP_CFLAGS
+: ${CFLAGS:=$PHP_CFLAGS}
+: ${CPPFLAGS:=$PHP_CPPFLAGS}
+: ${LDFLAGS:=$PHP_LDFLAGS}
+export CFLAGS CPPFLAGS LDFLAGS
+
 srcExists=
 if [ -d /usr/src/php ]; then
 	srcExists=1
diff --git a/7.0/zts/docker-php-ext-install b/7.0/zts/docker-php-ext-install
index 79df34e176..c06602302f 100755
--- a/7.0/zts/docker-php-ext-install
+++ b/7.0/zts/docker-php-ext-install
@@ -1,6 +1,12 @@
 #!/bin/sh
 set -e
 
+# prefer user supplied CFLAGS, but default to our PHP_CFLAGS
+: ${CFLAGS:=$PHP_CFLAGS}
+: ${CPPFLAGS:=$PHP_CPPFLAGS}
+: ${LDFLAGS:=$PHP_LDFLAGS}
+export CFLAGS CPPFLAGS LDFLAGS
+
 srcExists=
 if [ -d /usr/src/php ]; then
 	srcExists=1
diff --git a/7.1/Dockerfile b/7.1/Dockerfile
index 9acdbc82e7..5668b5de13 100644
--- a/7.1/Dockerfile
+++ b/7.1/Dockerfile
@@ -38,9 +38,9 @@ RUN mkdir -p $PHP_INI_DIR/conf.d
 # Enable linker optimization (this sorts the hash buckets to improve cache locality, and is non-default)
 # Adds GNU HASH segments to generated executables (this is used if present, and is much faster than sysv hash; in this configuration, sysv hash is also generated)
 # https://github.com/docker-library/php/issues/272
-ENV CFLAGS="-fstack-protector-strong -fpic -fpie -O2"
-ENV CPPFLAGS="$CFLAGS"
-ENV LDFLAGS="-Wl,-O1 -Wl,--hash-style=both"
+ENV PHP_CFLAGS="-fstack-protector-strong -fpic -fpie -O2"
+ENV PHP_CPPFLAGS="$PHP_CFLAGS"
+ENV PHP_LDFLAGS="-Wl,-O1 -Wl,--hash-style=both -pie"
 
 ENV GPG_KEYS A917B1ECDA84AEC2B568FED6F50ABC807BD5DCD0
 
@@ -94,6 +94,9 @@ RUN set -xe \
 	" \
 	&& apt-get update && apt-get install -y $buildDeps --no-install-recommends && rm -rf /var/lib/apt/lists/* \
 	\
+	&& export CFLAGS="$PHP_CFLAGS" \
+		CPPFLAGS="$PHP_CPPFLAGS" \
+		LDFLAGS="$PHP_LDFLAGS" \
 	&& docker-php-source extract \
 	&& cd /usr/src/php \
 	&& ./configure \
diff --git a/7.1/alpine/Dockerfile b/7.1/alpine/Dockerfile
index 5f3cd9aee7..92f6de810a 100644
--- a/7.1/alpine/Dockerfile
+++ b/7.1/alpine/Dockerfile
@@ -43,9 +43,9 @@ RUN mkdir -p $PHP_INI_DIR/conf.d
 # Enable linker optimization (this sorts the hash buckets to improve cache locality, and is non-default)
 # Adds GNU HASH segments to generated executables (this is used if present, and is much faster than sysv hash; in this configuration, sysv hash is also generated)
 # https://github.com/docker-library/php/issues/272
-ENV CFLAGS="-fstack-protector-strong -fpic -fpie -O2"
-ENV CPPFLAGS="$CFLAGS"
-ENV LDFLAGS="-Wl,-O1 -Wl,--hash-style=both"
+ENV PHP_CFLAGS="-fstack-protector-strong -fpic -fpie -O2"
+ENV PHP_CPPFLAGS="$PHP_CFLAGS"
+ENV PHP_LDFLAGS="-Wl,-O1 -Wl,--hash-style=both -pie"
 
 ENV GPG_KEYS A917B1ECDA84AEC2B568FED6F50ABC807BD5DCD0
 
@@ -95,6 +95,9 @@ RUN set -xe \
 		openssl-dev \
 		sqlite-dev \
 	\
+	&& export CFLAGS="$PHP_CFLAGS" \
+		CPPFLAGS="$PHP_CPPFLAGS" \
+		LDFLAGS="$PHP_LDFLAGS" \
 	&& docker-php-source extract \
 	&& cd /usr/src/php \
 	&& ./configure \
diff --git a/7.1/alpine/docker-php-ext-configure b/7.1/alpine/docker-php-ext-configure
index 2a6f8394ea..93d31601c9 100755
--- a/7.1/alpine/docker-php-ext-configure
+++ b/7.1/alpine/docker-php-ext-configure
@@ -1,6 +1,12 @@
 #!/bin/sh
 set -e
 
+# prefer user supplied CFLAGS, but default to our PHP_CFLAGS
+: ${CFLAGS:=$PHP_CFLAGS}
+: ${CPPFLAGS:=$PHP_CPPFLAGS}
+: ${LDFLAGS:=$PHP_LDFLAGS}
+export CFLAGS CPPFLAGS LDFLAGS
+
 srcExists=
 if [ -d /usr/src/php ]; then
 	srcExists=1
diff --git a/7.1/alpine/docker-php-ext-install b/7.1/alpine/docker-php-ext-install
index 79df34e176..c06602302f 100755
--- a/7.1/alpine/docker-php-ext-install
+++ b/7.1/alpine/docker-php-ext-install
@@ -1,6 +1,12 @@
 #!/bin/sh
 set -e
 
+# prefer user supplied CFLAGS, but default to our PHP_CFLAGS
+: ${CFLAGS:=$PHP_CFLAGS}
+: ${CPPFLAGS:=$PHP_CPPFLAGS}
+: ${LDFLAGS:=$PHP_LDFLAGS}
+export CFLAGS CPPFLAGS LDFLAGS
+
 srcExists=
 if [ -d /usr/src/php ]; then
 	srcExists=1
diff --git a/7.1/apache/Dockerfile b/7.1/apache/Dockerfile
index a29b6a08d0..592736ee4d 100644
--- a/7.1/apache/Dockerfile
+++ b/7.1/apache/Dockerfile
@@ -94,9 +94,9 @@ ENV PHP_EXTRA_CONFIGURE_ARGS --with-apxs2
 # Enable linker optimization (this sorts the hash buckets to improve cache locality, and is non-default)
 # Adds GNU HASH segments to generated executables (this is used if present, and is much faster than sysv hash; in this configuration, sysv hash is also generated)
 # https://github.com/docker-library/php/issues/272
-ENV CFLAGS="-fstack-protector-strong -fpic -fpie -O2"
-ENV CPPFLAGS="$CFLAGS"
-ENV LDFLAGS="-Wl,-O1 -Wl,--hash-style=both"
+ENV PHP_CFLAGS="-fstack-protector-strong -fpic -fpie -O2"
+ENV PHP_CPPFLAGS="$PHP_CFLAGS"
+ENV PHP_LDFLAGS="-Wl,-O1 -Wl,--hash-style=both -pie"
 
 ENV GPG_KEYS A917B1ECDA84AEC2B568FED6F50ABC807BD5DCD0
 
@@ -150,6 +150,9 @@ RUN set -xe \
 	" \
 	&& apt-get update && apt-get install -y $buildDeps --no-install-recommends && rm -rf /var/lib/apt/lists/* \
 	\
+	&& export CFLAGS="$PHP_CFLAGS" \
+		CPPFLAGS="$PHP_CPPFLAGS" \
+		LDFLAGS="$PHP_LDFLAGS" \
 	&& docker-php-source extract \
 	&& cd /usr/src/php \
 	&& ./configure \
diff --git a/7.1/apache/docker-php-ext-configure b/7.1/apache/docker-php-ext-configure
index 2a6f8394ea..93d31601c9 100755
--- a/7.1/apache/docker-php-ext-configure
+++ b/7.1/apache/docker-php-ext-configure
@@ -1,6 +1,12 @@
 #!/bin/sh
 set -e
 
+# prefer user supplied CFLAGS, but default to our PHP_CFLAGS
+: ${CFLAGS:=$PHP_CFLAGS}
+: ${CPPFLAGS:=$PHP_CPPFLAGS}
+: ${LDFLAGS:=$PHP_LDFLAGS}
+export CFLAGS CPPFLAGS LDFLAGS
+
 srcExists=
 if [ -d /usr/src/php ]; then
 	srcExists=1
diff --git a/7.1/apache/docker-php-ext-install b/7.1/apache/docker-php-ext-install
index 79df34e176..c06602302f 100755
--- a/7.1/apache/docker-php-ext-install
+++ b/7.1/apache/docker-php-ext-install
@@ -1,6 +1,12 @@
 #!/bin/sh
 set -e
 
+# prefer user supplied CFLAGS, but default to our PHP_CFLAGS
+: ${CFLAGS:=$PHP_CFLAGS}
+: ${CPPFLAGS:=$PHP_CPPFLAGS}
+: ${LDFLAGS:=$PHP_LDFLAGS}
+export CFLAGS CPPFLAGS LDFLAGS
+
 srcExists=
 if [ -d /usr/src/php ]; then
 	srcExists=1
diff --git a/7.1/docker-php-ext-configure b/7.1/docker-php-ext-configure
index 2a6f8394ea..93d31601c9 100755
--- a/7.1/docker-php-ext-configure
+++ b/7.1/docker-php-ext-configure
@@ -1,6 +1,12 @@
 #!/bin/sh
 set -e
 
+# prefer user supplied CFLAGS, but default to our PHP_CFLAGS
+: ${CFLAGS:=$PHP_CFLAGS}
+: ${CPPFLAGS:=$PHP_CPPFLAGS}
+: ${LDFLAGS:=$PHP_LDFLAGS}
+export CFLAGS CPPFLAGS LDFLAGS
+
 srcExists=
 if [ -d /usr/src/php ]; then
 	srcExists=1
diff --git a/7.1/docker-php-ext-install b/7.1/docker-php-ext-install
index 79df34e176..c06602302f 100755
--- a/7.1/docker-php-ext-install
+++ b/7.1/docker-php-ext-install
@@ -1,6 +1,12 @@
 #!/bin/sh
 set -e
 
+# prefer user supplied CFLAGS, but default to our PHP_CFLAGS
+: ${CFLAGS:=$PHP_CFLAGS}
+: ${CPPFLAGS:=$PHP_CPPFLAGS}
+: ${LDFLAGS:=$PHP_LDFLAGS}
+export CFLAGS CPPFLAGS LDFLAGS
+
 srcExists=
 if [ -d /usr/src/php ]; then
 	srcExists=1
diff --git a/7.1/fpm/Dockerfile b/7.1/fpm/Dockerfile
index adf9cca62b..9cc7c35d8a 100644
--- a/7.1/fpm/Dockerfile
+++ b/7.1/fpm/Dockerfile
@@ -39,9 +39,9 @@ ENV PHP_EXTRA_CONFIGURE_ARGS --enable-fpm --with-fpm-user=www-data --with-fpm-gr
 # Enable linker optimization (this sorts the hash buckets to improve cache locality, and is non-default)
 # Adds GNU HASH segments to generated executables (this is used if present, and is much faster than sysv hash; in this configuration, sysv hash is also generated)
 # https://github.com/docker-library/php/issues/272
-ENV CFLAGS="-fstack-protector-strong -fpic -fpie -O2"
-ENV CPPFLAGS="$CFLAGS"
-ENV LDFLAGS="-Wl,-O1 -Wl,--hash-style=both"
+ENV PHP_CFLAGS="-fstack-protector-strong -fpic -fpie -O2"
+ENV PHP_CPPFLAGS="$PHP_CFLAGS"
+ENV PHP_LDFLAGS="-Wl,-O1 -Wl,--hash-style=both -pie"
 
 ENV GPG_KEYS A917B1ECDA84AEC2B568FED6F50ABC807BD5DCD0
 
@@ -95,6 +95,9 @@ RUN set -xe \
 	" \
 	&& apt-get update && apt-get install -y $buildDeps --no-install-recommends && rm -rf /var/lib/apt/lists/* \
 	\
+	&& export CFLAGS="$PHP_CFLAGS" \
+		CPPFLAGS="$PHP_CPPFLAGS" \
+		LDFLAGS="$PHP_LDFLAGS" \
 	&& docker-php-source extract \
 	&& cd /usr/src/php \
 	&& ./configure \
diff --git a/7.1/fpm/alpine/Dockerfile b/7.1/fpm/alpine/Dockerfile
index af61e203e2..31dab76360 100644
--- a/7.1/fpm/alpine/Dockerfile
+++ b/7.1/fpm/alpine/Dockerfile
@@ -44,9 +44,9 @@ ENV PHP_EXTRA_CONFIGURE_ARGS --enable-fpm --with-fpm-user=www-data --with-fpm-gr
 # Enable linker optimization (this sorts the hash buckets to improve cache locality, and is non-default)
 # Adds GNU HASH segments to generated executables (this is used if present, and is much faster than sysv hash; in this configuration, sysv hash is also generated)
 # https://github.com/docker-library/php/issues/272
-ENV CFLAGS="-fstack-protector-strong -fpic -fpie -O2"
-ENV CPPFLAGS="$CFLAGS"
-ENV LDFLAGS="-Wl,-O1 -Wl,--hash-style=both"
+ENV PHP_CFLAGS="-fstack-protector-strong -fpic -fpie -O2"
+ENV PHP_CPPFLAGS="$PHP_CFLAGS"
+ENV PHP_LDFLAGS="-Wl,-O1 -Wl,--hash-style=both -pie"
 
 ENV GPG_KEYS A917B1ECDA84AEC2B568FED6F50ABC807BD5DCD0
 
@@ -96,6 +96,9 @@ RUN set -xe \
 		openssl-dev \
 		sqlite-dev \
 	\
+	&& export CFLAGS="$PHP_CFLAGS" \
+		CPPFLAGS="$PHP_CPPFLAGS" \
+		LDFLAGS="$PHP_LDFLAGS" \
 	&& docker-php-source extract \
 	&& cd /usr/src/php \
 	&& ./configure \
diff --git a/7.1/fpm/alpine/docker-php-ext-configure b/7.1/fpm/alpine/docker-php-ext-configure
index 2a6f8394ea..93d31601c9 100755
--- a/7.1/fpm/alpine/docker-php-ext-configure
+++ b/7.1/fpm/alpine/docker-php-ext-configure
@@ -1,6 +1,12 @@
 #!/bin/sh
 set -e
 
+# prefer user supplied CFLAGS, but default to our PHP_CFLAGS
+: ${CFLAGS:=$PHP_CFLAGS}
+: ${CPPFLAGS:=$PHP_CPPFLAGS}
+: ${LDFLAGS:=$PHP_LDFLAGS}
+export CFLAGS CPPFLAGS LDFLAGS
+
 srcExists=
 if [ -d /usr/src/php ]; then
 	srcExists=1
diff --git a/7.1/fpm/alpine/docker-php-ext-install b/7.1/fpm/alpine/docker-php-ext-install
index 79df34e176..c06602302f 100755
--- a/7.1/fpm/alpine/docker-php-ext-install
+++ b/7.1/fpm/alpine/docker-php-ext-install
@@ -1,6 +1,12 @@
 #!/bin/sh
 set -e
 
+# prefer user supplied CFLAGS, but default to our PHP_CFLAGS
+: ${CFLAGS:=$PHP_CFLAGS}
+: ${CPPFLAGS:=$PHP_CPPFLAGS}
+: ${LDFLAGS:=$PHP_LDFLAGS}
+export CFLAGS CPPFLAGS LDFLAGS
+
 srcExists=
 if [ -d /usr/src/php ]; then
 	srcExists=1
diff --git a/7.1/fpm/docker-php-ext-configure b/7.1/fpm/docker-php-ext-configure
index 2a6f8394ea..93d31601c9 100755
--- a/7.1/fpm/docker-php-ext-configure
+++ b/7.1/fpm/docker-php-ext-configure
@@ -1,6 +1,12 @@
 #!/bin/sh
 set -e
 
+# prefer user supplied CFLAGS, but default to our PHP_CFLAGS
+: ${CFLAGS:=$PHP_CFLAGS}
+: ${CPPFLAGS:=$PHP_CPPFLAGS}
+: ${LDFLAGS:=$PHP_LDFLAGS}
+export CFLAGS CPPFLAGS LDFLAGS
+
 srcExists=
 if [ -d /usr/src/php ]; then
 	srcExists=1
diff --git a/7.1/fpm/docker-php-ext-install b/7.1/fpm/docker-php-ext-install
index 79df34e176..c06602302f 100755
--- a/7.1/fpm/docker-php-ext-install
+++ b/7.1/fpm/docker-php-ext-install
@@ -1,6 +1,12 @@
 #!/bin/sh
 set -e
 
+# prefer user supplied CFLAGS, but default to our PHP_CFLAGS
+: ${CFLAGS:=$PHP_CFLAGS}
+: ${CPPFLAGS:=$PHP_CPPFLAGS}
+: ${LDFLAGS:=$PHP_LDFLAGS}
+export CFLAGS CPPFLAGS LDFLAGS
+
 srcExists=
 if [ -d /usr/src/php ]; then
 	srcExists=1
diff --git a/7.1/zts/Dockerfile b/7.1/zts/Dockerfile
index 334efebb8b..fcb111e889 100644
--- a/7.1/zts/Dockerfile
+++ b/7.1/zts/Dockerfile
@@ -39,9 +39,9 @@ ENV PHP_EXTRA_CONFIGURE_ARGS --enable-maintainer-zts
 # Enable linker optimization (this sorts the hash buckets to improve cache locality, and is non-default)
 # Adds GNU HASH segments to generated executables (this is used if present, and is much faster than sysv hash; in this configuration, sysv hash is also generated)
 # https://github.com/docker-library/php/issues/272
-ENV CFLAGS="-fstack-protector-strong -fpic -fpie -O2"
-ENV CPPFLAGS="$CFLAGS"
-ENV LDFLAGS="-Wl,-O1 -Wl,--hash-style=both"
+ENV PHP_CFLAGS="-fstack-protector-strong -fpic -fpie -O2"
+ENV PHP_CPPFLAGS="$PHP_CFLAGS"
+ENV PHP_LDFLAGS="-Wl,-O1 -Wl,--hash-style=both -pie"
 
 ENV GPG_KEYS A917B1ECDA84AEC2B568FED6F50ABC807BD5DCD0
 
@@ -95,6 +95,9 @@ RUN set -xe \
 	" \
 	&& apt-get update && apt-get install -y $buildDeps --no-install-recommends && rm -rf /var/lib/apt/lists/* \
 	\
+	&& export CFLAGS="$PHP_CFLAGS" \
+		CPPFLAGS="$PHP_CPPFLAGS" \
+		LDFLAGS="$PHP_LDFLAGS" \
 	&& docker-php-source extract \
 	&& cd /usr/src/php \
 	&& ./configure \
diff --git a/7.1/zts/alpine/Dockerfile b/7.1/zts/alpine/Dockerfile
index 47c0a98a8c..dc8e02fc01 100644
--- a/7.1/zts/alpine/Dockerfile
+++ b/7.1/zts/alpine/Dockerfile
@@ -44,9 +44,9 @@ ENV PHP_EXTRA_CONFIGURE_ARGS --enable-maintainer-zts
 # Enable linker optimization (this sorts the hash buckets to improve cache locality, and is non-default)
 # Adds GNU HASH segments to generated executables (this is used if present, and is much faster than sysv hash; in this configuration, sysv hash is also generated)
 # https://github.com/docker-library/php/issues/272
-ENV CFLAGS="-fstack-protector-strong -fpic -fpie -O2"
-ENV CPPFLAGS="$CFLAGS"
-ENV LDFLAGS="-Wl,-O1 -Wl,--hash-style=both"
+ENV PHP_CFLAGS="-fstack-protector-strong -fpic -fpie -O2"
+ENV PHP_CPPFLAGS="$PHP_CFLAGS"
+ENV PHP_LDFLAGS="-Wl,-O1 -Wl,--hash-style=both -pie"
 
 ENV GPG_KEYS A917B1ECDA84AEC2B568FED6F50ABC807BD5DCD0
 
@@ -96,6 +96,9 @@ RUN set -xe \
 		openssl-dev \
 		sqlite-dev \
 	\
+	&& export CFLAGS="$PHP_CFLAGS" \
+		CPPFLAGS="$PHP_CPPFLAGS" \
+		LDFLAGS="$PHP_LDFLAGS" \
 	&& docker-php-source extract \
 	&& cd /usr/src/php \
 	&& ./configure \
diff --git a/7.1/zts/alpine/docker-php-ext-configure b/7.1/zts/alpine/docker-php-ext-configure
index 2a6f8394ea..93d31601c9 100755
--- a/7.1/zts/alpine/docker-php-ext-configure
+++ b/7.1/zts/alpine/docker-php-ext-configure
@@ -1,6 +1,12 @@
 #!/bin/sh
 set -e
 
+# prefer user supplied CFLAGS, but default to our PHP_CFLAGS
+: ${CFLAGS:=$PHP_CFLAGS}
+: ${CPPFLAGS:=$PHP_CPPFLAGS}
+: ${LDFLAGS:=$PHP_LDFLAGS}
+export CFLAGS CPPFLAGS LDFLAGS
+
 srcExists=
 if [ -d /usr/src/php ]; then
 	srcExists=1
diff --git a/7.1/zts/alpine/docker-php-ext-install b/7.1/zts/alpine/docker-php-ext-install
index 79df34e176..c06602302f 100755
--- a/7.1/zts/alpine/docker-php-ext-install
+++ b/7.1/zts/alpine/docker-php-ext-install
@@ -1,6 +1,12 @@
 #!/bin/sh
 set -e
 
+# prefer user supplied CFLAGS, but default to our PHP_CFLAGS
+: ${CFLAGS:=$PHP_CFLAGS}
+: ${CPPFLAGS:=$PHP_CPPFLAGS}
+: ${LDFLAGS:=$PHP_LDFLAGS}
+export CFLAGS CPPFLAGS LDFLAGS
+
 srcExists=
 if [ -d /usr/src/php ]; then
 	srcExists=1
diff --git a/7.1/zts/docker-php-ext-configure b/7.1/zts/docker-php-ext-configure
index 2a6f8394ea..93d31601c9 100755
--- a/7.1/zts/docker-php-ext-configure
+++ b/7.1/zts/docker-php-ext-configure
@@ -1,6 +1,12 @@
 #!/bin/sh
 set -e
 
+# prefer user supplied CFLAGS, but default to our PHP_CFLAGS
+: ${CFLAGS:=$PHP_CFLAGS}
+: ${CPPFLAGS:=$PHP_CPPFLAGS}
+: ${LDFLAGS:=$PHP_LDFLAGS}
+export CFLAGS CPPFLAGS LDFLAGS
+
 srcExists=
 if [ -d /usr/src/php ]; then
 	srcExists=1
diff --git a/7.1/zts/docker-php-ext-install b/7.1/zts/docker-php-ext-install
index 79df34e176..c06602302f 100755
--- a/7.1/zts/docker-php-ext-install
+++ b/7.1/zts/docker-php-ext-install
@@ -1,6 +1,12 @@
 #!/bin/sh
 set -e
 
+# prefer user supplied CFLAGS, but default to our PHP_CFLAGS
+: ${CFLAGS:=$PHP_CFLAGS}
+: ${CPPFLAGS:=$PHP_CPPFLAGS}
+: ${LDFLAGS:=$PHP_LDFLAGS}
+export CFLAGS CPPFLAGS LDFLAGS
+
 srcExists=
 if [ -d /usr/src/php ]; then
 	srcExists=1
diff --git a/Dockerfile-alpine.template b/Dockerfile-alpine.template
index 43e4097423..1404280f98 100644
--- a/Dockerfile-alpine.template
+++ b/Dockerfile-alpine.template
@@ -37,9 +37,9 @@ RUN mkdir -p $PHP_INI_DIR/conf.d
 # Enable linker optimization (this sorts the hash buckets to improve cache locality, and is non-default)
 # Adds GNU HASH segments to generated executables (this is used if present, and is much faster than sysv hash; in this configuration, sysv hash is also generated)
 # https://github.com/docker-library/php/issues/272
-ENV CFLAGS="-fstack-protector-strong -fpic -fpie -O2"
-ENV CPPFLAGS="$CFLAGS"
-ENV LDFLAGS="-Wl,-O1 -Wl,--hash-style=both"
+ENV PHP_CFLAGS="-fstack-protector-strong -fpic -fpie -O2"
+ENV PHP_CPPFLAGS="$PHP_CFLAGS"
+ENV PHP_LDFLAGS="-Wl,-O1 -Wl,--hash-style=both -pie"
 
 ENV GPG_KEYS %%GPG_KEYS%%
 
@@ -89,6 +89,9 @@ RUN set -xe \
 		openssl-dev \
 		sqlite-dev \
 	\
+	&& export CFLAGS="$PHP_CFLAGS" \
+		CPPFLAGS="$PHP_CPPFLAGS" \
+		LDFLAGS="$PHP_LDFLAGS" \
 	&& docker-php-source extract \
 	&& cd /usr/src/php \
 	&& ./configure \
diff --git a/Dockerfile-debian.template b/Dockerfile-debian.template
index 2f4de9cd82..896f1b17b1 100644
--- a/Dockerfile-debian.template
+++ b/Dockerfile-debian.template
@@ -32,9 +32,9 @@ RUN mkdir -p $PHP_INI_DIR/conf.d
 # Enable linker optimization (this sorts the hash buckets to improve cache locality, and is non-default)
 # Adds GNU HASH segments to generated executables (this is used if present, and is much faster than sysv hash; in this configuration, sysv hash is also generated)
 # https://github.com/docker-library/php/issues/272
-ENV CFLAGS="-fstack-protector-strong -fpic -fpie -O2"
-ENV CPPFLAGS="$CFLAGS"
-ENV LDFLAGS="-Wl,-O1 -Wl,--hash-style=both"
+ENV PHP_CFLAGS="-fstack-protector-strong -fpic -fpie -O2"
+ENV PHP_CPPFLAGS="$PHP_CFLAGS"
+ENV PHP_LDFLAGS="-Wl,-O1 -Wl,--hash-style=both -pie"
 
 ENV GPG_KEYS %%GPG_KEYS%%
 
@@ -88,6 +88,9 @@ RUN set -xe \
 	" \
 	&& apt-get update && apt-get install -y $buildDeps --no-install-recommends && rm -rf /var/lib/apt/lists/* \
 	\
+	&& export CFLAGS="$PHP_CFLAGS" \
+		CPPFLAGS="$PHP_CPPFLAGS" \
+		LDFLAGS="$PHP_LDFLAGS" \
 	&& docker-php-source extract \
 	&& cd /usr/src/php \
 	&& ./configure \
diff --git a/docker-php-ext-configure b/docker-php-ext-configure
index 2a6f8394ea..93d31601c9 100755
--- a/docker-php-ext-configure
+++ b/docker-php-ext-configure
@@ -1,6 +1,12 @@
 #!/bin/sh
 set -e
 
+# prefer user supplied CFLAGS, but default to our PHP_CFLAGS
+: ${CFLAGS:=$PHP_CFLAGS}
+: ${CPPFLAGS:=$PHP_CPPFLAGS}
+: ${LDFLAGS:=$PHP_LDFLAGS}
+export CFLAGS CPPFLAGS LDFLAGS
+
 srcExists=
 if [ -d /usr/src/php ]; then
 	srcExists=1
diff --git a/docker-php-ext-install b/docker-php-ext-install
index 79df34e176..c06602302f 100755
--- a/docker-php-ext-install
+++ b/docker-php-ext-install
@@ -1,6 +1,12 @@
 #!/bin/sh
 set -e
 
+# prefer user supplied CFLAGS, but default to our PHP_CFLAGS
+: ${CFLAGS:=$PHP_CFLAGS}
+: ${CPPFLAGS:=$PHP_CPPFLAGS}
+: ${LDFLAGS:=$PHP_LDFLAGS}
+export CFLAGS CPPFLAGS LDFLAGS
+
 srcExists=
 if [ -d /usr/src/php ]; then
 	srcExists=1