diff --git a/src/codegen.cpp b/src/codegen.cpp
index aca1f9f10d429..55b8aafba0118 100644
--- a/src/codegen.cpp
+++ b/src/codegen.cpp
@@ -989,10 +989,8 @@ void *jl_function_ptr(jl_function_t *f, jl_value_t *rt, jl_value_t *argt)
 // it generally helps to have define KEEP_BODIES if you plan on using this
 extern "C" JL_DLLEXPORT
 void *jl_function_ptr_by_llvm_name(char *name) {
-#ifdef __has_feature
-#if __has_feature(memory_sanitizer)
+#ifdef JL_MSAN_ENABLED
     __msan_unpoison_string(name);
-#endif
 #endif
     return (void*)(intptr_t)jl_ExecutionEngine->FindFunctionNamed(name);
 }
diff --git a/src/dlload.c b/src/dlload.c
index da290a1f32a3c..1966c92803f58 100644
--- a/src/dlload.c
+++ b/src/dlload.c
@@ -54,11 +54,6 @@ static int endswith_extension(const char *path)
 extern char *julia_home;
 
 #define JL_RTLD(flags, FLAG) (flags & JL_RTLD_ ## FLAG ? RTLD_ ## FLAG : 0)
-#ifdef __has_feature
-#   if __has_feature(address_sanitizer)
-#      define SANITIZE_ADDRESS
-#   endif
-#endif
 
 static void JL_NORETURN jl_dlerror(const char *fmt, const char *sym)
 {
@@ -95,7 +90,7 @@ JL_DLLEXPORT void *jl_dlopen(const char *filename, unsigned flags)
 #ifdef RTLD_NOLOAD
                   | JL_RTLD(flags, NOLOAD)
 #endif
-#if defined(RTLD_DEEPBIND) && !defined(SANITIZE_ADDRESS)
+#if defined(RTLD_DEEPBIND) && !defined(JL_ASAN_ENABLED)
                   | JL_RTLD(flags, DEEPBIND)
 #endif
 #ifdef RTLD_FIRST
diff --git a/src/init.c b/src/init.c
index 53e2dd62b578f..cb4758b8c56c0 100644
--- a/src/init.c
+++ b/src/init.c
@@ -161,8 +161,8 @@ void jl_init_stack_limits(int ismaster)
 
 static void jl_find_stack_bottom(void)
 {
-#if !defined(_OS_WINDOWS_) && defined(__has_feature)
-#if __has_feature(memory_sanitizer) || __has_feature(address_sanitizer)
+#if !defined(_OS_WINDOWS_)
+#if defined(JL_ASAN_ENABLED) || defined(JL_MSAN_ENABLED)
     struct rlimit rl;
 
     // When using the sanitizers, increase stack size because they bloat
@@ -621,6 +621,17 @@ void _julia_init(JL_IMAGE_SEARCH rel)
     }
 #endif
 
+
+#ifdef JL_ASAN_ENABLED
+    const char *asan_options = getenv("ASAN_OPTIONS");
+    if (!asan_options || !(strstr(asan_options, "allow_user_segv_handler=1") ||
+                           strstr(asan_options, "handle_segv=0"))) {
+        jl_printf(JL_STDERR,"WARNING: ASAN overrides Julia's SIGSEGV handler; "
+                            "disable SIGSEGV handling or allow custom handlers.\n");
+    }
+
+#endif
+
     jl_init_threading();
 
     jl_gc_init();
diff --git a/src/jitlayers.cpp b/src/jitlayers.cpp
index 474f4e5feb59e..b8f02a88d50d9 100644
--- a/src/jitlayers.cpp
+++ b/src/jitlayers.cpp
@@ -102,17 +102,15 @@ void addOptimizationPasses(PassManager *PM)
     PM->add(createVerifierPass());
 #endif
 
-#ifdef __has_feature
-#   if __has_feature(address_sanitizer)
+#if defined(JL_ASAN_ENABLED)
 #   if defined(LLVM37) && !defined(LLVM38)
     // LLVM 3.7 BUG: ASAN pass doesn't properly initialize its dependencies
     initializeTargetLibraryInfoWrapperPassPass(*PassRegistry::getPassRegistry());
 #   endif
     PM->add(createAddressSanitizerFunctionPass());
-#   endif
-#   if __has_feature(memory_sanitizer)
+#endif
+#if defined(JL_MSAN_ENABLED)
     PM->add(llvm::createMemorySanitizerPass(true));
-#   endif
 #endif
     if (jl_options.opt_level == 0) {
         PM->add(createLowerPTLSPass(imaging_mode, tbaa_const));
diff --git a/src/julia_internal.h b/src/julia_internal.h
index d967de1ff00cb..2c7105b62e53c 100644
--- a/src/julia_internal.h
+++ b/src/julia_internal.h
@@ -12,6 +12,20 @@
 #define sleep(x) Sleep(1000*x)
 #endif
 
+#if defined(__has_feature)
+#if __has_feature(address_sanitizer)
+#define JL_ASAN_ENABLED     // Clang flavor
+#endif
+#elif defined(__SANITIZE_ADDRESS__)
+#define JL_ASAN_ENABLED     // GCC flavor
+#endif
+
+#if defined(__has_feature)
+#if __has_feature(memory_sanitizer)
+#define JL_MSAN_ENABLED
+#endif
+#endif
+
 #ifdef __cplusplus
 extern "C" {
 #endif
diff --git a/src/options.h b/src/options.h
index a6445b9f1f7e8..1f5af35b02edd 100644
--- a/src/options.h
+++ b/src/options.h
@@ -67,6 +67,9 @@
 // OBJPROFILE counts objects by type
 // #define OBJPROFILE
 
+// Automatic Instrumenting Profiler
+//#define ENABLE_TIMINGS
+
 
 // method dispatch profiling --------------------------------------------------
 
@@ -93,6 +96,7 @@
 #define COPY_STACKS
 #endif
 
+
 // threading options ----------------------------------------------------------
 
 // controls for when threads sleep
@@ -109,21 +113,32 @@
 #define MACHINE_EXCLUSIVE_NAME          "JULIA_EXCLUSIVE"
 #define DEFAULT_MACHINE_EXCLUSIVE       0
 
+
 // sanitizer defaults ---------------------------------------------------------
 
-// Automatically enable MEMDEBUG and KEEP_BODIES for the sanitizers
+// XXX: these macros are duplicated from julia_internal.h
 #if defined(__has_feature)
-#  if __has_feature(address_sanitizer) || __has_feature(memory_sanitizer)
-#  define MEMDEBUG
-#  define KEEP_BODIES
-#  endif
-// Memory sanitizer needs TLS, which llvm only supports for the small memory model
-#  if __has_feature(memory_sanitizer)
-   // todo: fix the llvm MemoryManager to work with small memory model
-#  endif
+#if __has_feature(address_sanitizer)
+#define JL_ASAN_ENABLED
+#endif
+#elif defined(__SANITIZE_ADDRESS__)
+#define JL_ASAN_ENABLED
+#endif
+#if defined(__has_feature)
+#if __has_feature(memory_sanitizer)
+#define JL_MSAN_ENABLED
+#endif
 #endif
 
-// Automatic Instrumenting Profiler
-//#define ENABLE_TIMINGS
+// Automatically enable MEMDEBUG and KEEP_BODIES for the sanitizers
+#if defined(JL_ASAN_ENABLED) || defined(JL_MSAN_ENABLED)
+#define MEMDEBUG
+#define KEEP_BODIES
+#endif
+
+// Memory sanitizer needs TLS, which llvm only supports for the small memory model
+#if defined(JL_MSAN_ENABLED)
+// todo: fix the llvm MemoryManager to work with small memory model
+#endif
 
 #endif
diff --git a/src/sys.c b/src/sys.c
index 3406a8a7e11dc..0723b3dc60bf1 100644
--- a/src/sys.c
+++ b/src/sys.c
@@ -48,11 +48,9 @@
 #include <intrin.h>
 #endif
 
-#ifdef __has_feature
-#if __has_feature(memory_sanitizer)
+#ifdef JL_MSAN_ENABLED
 #include <sanitizer/msan_interface.h>
 #endif
-#endif
 
 #ifdef __cplusplus
 extern "C" {
@@ -663,14 +661,12 @@ JL_DLLEXPORT const char *jl_pathname_for_handle(void *handle)
 
     struct link_map *map;
     dlinfo(handle, RTLD_DI_LINKMAP, &map);
-#ifdef __has_feature
-#if __has_feature(memory_sanitizer)
+#ifdef JL_MSAN_ENABLED
     __msan_unpoison(&map,sizeof(struct link_map*));
     if (map) {
         __msan_unpoison(map, sizeof(struct link_map));
         __msan_unpoison_string(map->l_name);
     }
-#endif
 #endif
     if (map)
         return map->l_name;