diff --git a/config/opal_configure_options.m4 b/config/opal_configure_options.m4
index 6f4db08f2b4..d94200a6e4f 100644
--- a/config/opal_configure_options.m4
+++ b/config/opal_configure_options.m4
@@ -356,29 +356,6 @@ AC_DEFINE_UNQUOTED([OPAL_ENABLE_HETEROGENEOUS_SUPPORT],
                    [Enable features required for heterogeneous support])
 
 
-if test "$opal_want_heterogeneous" = 1; then
-    ompi_cv_c_word_size_align=yes
-else
-    AC_CACHE_CHECK([if word-sized integers must be word-size aligned],
-        [ompi_cv_c_word_size_align],
-        [AC_LANG_PUSH(C)
-         AC_RUN_IFELSE([AC_LANG_PROGRAM([dnl
-#include <stdlib.h>], [[    long data[2] = {0, 0};
-    long *lp;
-    int *ip;
-    ip = (int*) data;
-    ip++;
-    lp = (long*) ip;
-    return lp[0]; ]])],
-            [ompi_cv_c_word_size_align=no],
-            [ompi_cv_c_word_size_align=yes],
-            [ompi_cv_c_word_size_align=yes])])
-fi
-AS_IF([test $ompi_cv_c_word_size_align = yes], [results=1], [results=0])
-AC_DEFINE_UNQUOTED([OPAL_ALIGN_WORD_SIZE_INTEGERS], [$results],
-    [set to 1 if word-size integers must be aligned to word-size padding to prevent bus errors])
-
-
 #
 # Cross-compile data
 #
diff --git a/config/opal_mca.m4 b/config/opal_mca.m4
index fcd75f5c6a3..070507a1fbd 100644
--- a/config/opal_mca.m4
+++ b/config/opal_mca.m4
@@ -43,6 +43,8 @@ AC_DEFUN([OPAL_EVAL_ARG], [$1])
 AC_DEFUN([OPAL_MCA],[
     dnl for OPAL_CONFIGURE_USER env variable
     AC_REQUIRE([OPAL_CONFIGURE_SETUP])
+    dnl For all the path management
+    AC_REQUIRE([OPAL_SETUP_WRAPPER_INIT])
 
     # Set a special flag so that we can detect if the user calls
     # OPAL_WRAPPER_FLAGS_ADD and error.
diff --git a/config/opal_setup_cc.m4 b/config/opal_setup_cc.m4
index ba3d99f819e..dba0d5978d0 100644
--- a/config/opal_setup_cc.m4
+++ b/config/opal_setup_cc.m4
@@ -424,18 +424,34 @@ AC_DEFUN([_OPAL_START_SETUP_CC],[
 
 
 AC_DEFUN([_OPAL_PROG_CC],[
+    dnl It is really easy to accidently call AC_PROG_CC implicitly through
+    dnl some other test run before OPAL_SETUP_CC.  Try to make that harder.
+    m4_provide_if([AC_PROG_CC],
+                  [m4_fatal([AC_PROG_CC called before OPAL_SETUP_CC])])
+
     #
     # Check for the compiler
     #
     OPAL_VAR_SCOPE_PUSH([opal_cflags_save dummy opal_cc_arvgv0])
+
+    # AC_USE_SYSTEM_EXTENSIONS alters CFLAGS (e.g., adds -g -O2)
+    opal_cflags_save="$CFLAGS"
+    AC_USE_SYSTEM_EXTENSIONS
+    # AC_USE_SYSTEM_EXTENSIONS will modify CFLAGS if nothing was in there
+    # beforehand.  We don't want that.  So if there was nothing in
+    # CFLAGS, put nothing back in there.
+    AS_IF([test -z "$opal_cflags_save"], [CFLAGS=])
+
     opal_cflags_save="$CFLAGS"
     AC_PROG_CC
     BASECC="`basename $CC`"
     CFLAGS="$opal_cflags_save"
-    AC_DEFINE_UNQUOTED(OPAL_CC, "$CC", [OMPI underlying C compiler])
+    OPAL_CC="$CC"
+    AC_DEFINE_UNQUOTED(OPAL_CC, "$OPAL_CC", [OMPI underlying C compiler])
     set dummy $CC
     opal_cc_argv0=[$]2
     OPAL_WHICH([$opal_cc_argv0], [OPAL_CC_ABSOLUTE])
     AC_SUBST(OPAL_CC_ABSOLUTE)
+
     OPAL_VAR_SCOPE_POP
 ])
diff --git a/config/opal_setup_wrappers.m4 b/config/opal_setup_wrappers.m4
index 35015d19490..727e70ce815 100644
--- a/config/opal_setup_wrappers.m4
+++ b/config/opal_setup_wrappers.m4
@@ -79,13 +79,16 @@ AC_DEFUN([OPAL_WRAPPER_FLAGS_ADD], [
 #     <flag>_prefix, configure is not.  There's no known use case for
 #     doing so, and we'd like to force the issue.
 AC_DEFUN([OPAL_SETUP_WRAPPER_INIT],[
+    dnl for OPAL_CC
+    AC_REQUIRE([OPAL_SETUP_CC])
+
+    opal_show_subtitle "Wrapper compiler setup"
+
     OPAL_VAR_SCOPE_PUSH([wrapper_cc_tmp])
-    # AC_PROG_CC_C99 changes CC (instead of CFLAGS) so this method
-    # must be called before OPAL_SETUP_CC.
     AC_ARG_WITH([wrapper_cc],
 		[AS_HELP_STRING([--with-wrapper-cc=path],
 				[Set a different wrapper C compiler than the one used to build Open MPI])],
-		[], [with_wrapper_cc="$CC"])
+		[], [with_wrapper_cc="$OPAL_CC"])
 
     AC_MSG_CHECKING([for wrapper C compiler])
 
diff --git a/config/oshmem_configure_options.m4 b/config/oshmem_configure_options.m4
index 0ceac244b40..8290b9684ac 100644
--- a/config/oshmem_configure_options.m4
+++ b/config/oshmem_configure_options.m4
@@ -28,22 +28,30 @@ AC_MSG_CHECKING([if want oshmem])
 AC_ARG_ENABLE([oshmem],
               [AS_HELP_STRING([--enable-oshmem],
                               [Enable building the OpenSHMEM interface (available on Linux only, where it is enabled by default)])])
+
 if test "$enable_oshmem" = "no"; then
     AC_MSG_RESULT([no])
 elif test "$enable_oshmem" = ""; then
-    if test "$opal_found_linux" = "yes"; then
+    case $host_os in
+    linux*)
         AC_MSG_RESULT([yes])
-    else
+        ;;
+    *)
         enable_oshmem=no
         AC_MSG_RESULT([not supported on this platform])
-    fi
+        ;;
+    esac
 else
     AC_MSG_RESULT([yes])
-    if test "$opal_found_linux" != "yes"; then
+    case $host_os in
+    linux*)
+	;;
+    *)
         AC_MSG_WARN([OpenSHMEM support was requested, but currently])
         AC_MSG_WARN([only supports Linux.])
         AC_MSG_ERROR([Cannot continue])
-    fi
+        ;;
+    esac
 fi
 
 #
@@ -91,11 +99,6 @@ fi
 AC_DEFINE_UNQUOTED(OSHMEM_PARAM_CHECK, $shmem_param_check,
     [Whether we want to check OSHMEM parameters always or never])
 
-#
-# check for on_exit
-#
-AC_CHECK_FUNCS([on_exit])
-
 #
 #  OSHMEM profiling support
 #
diff --git a/configure.ac b/configure.ac
index 86d0df1e29a..e53ef380a5f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -93,15 +93,6 @@ AS_IF([test "$host" != "$target"],
        AC_MSG_WARN([Cross-compiling is only partially supported])
        AC_MSG_WARN([Proceed at your own risk!])])
 
-# AC_USE_SYSTEM_EXTENSIONS alters CFLAGS (e.g., adds -g -O2)
-OPAL_VAR_SCOPE_PUSH([CFLAGS_save])
-CFLAGS_save=$CFLAGS
-AC_USE_SYSTEM_EXTENSIONS
-# AC_USE_SYSTEM_EXTENSIONS will modify CFLAGS if nothing was in there
-# beforehand.  We don't want that.  So if there was nothing in
-# CFLAGS, put nothing back in there.
-AS_IF([test -z "$CFLAGS_save"], [CFLAGS=])
-OPAL_VAR_SCOPE_POP
 
 #
 # Init automake
@@ -290,8 +281,6 @@ m4_ifdef([project_oshmem],
 ############################################################################
 
 OPAL_CONFIGURE_OPTIONS
-OPAL_CHECK_OS_FLAVORS
-OPAL_CHECK_CUDA
 
 m4_ifdef([project_ompi], [OMPI_CONFIGURE_OPTIONS])
 m4_ifdef([project_oshmem], [OSHMEM_CONFIGURE_OPTIONS])
@@ -346,10 +335,6 @@ m4_ifdef([project_ompi],
 AC_ENABLE_SHARED
 AC_DISABLE_STATIC
 
-# Must be called before OPAL_SETUP_CC to get the value of CC
-# before it is modified by the C99/C11 checks.
-OPAL_SETUP_WRAPPER_INIT
-
 ##################################
 # Check for known incompatibility
 ##################################
@@ -550,6 +535,29 @@ OPAL_C_GET_ALIGNMENT(size_t, OPAL_ALIGNMENT_SIZE_T)
 
 OPAL_CHECK_ALT_SHORT_FLOAT
 
+# Check system alignment requirements
+if test "$opal_want_heterogeneous" = 1; then
+    ompi_cv_c_word_size_align=yes
+else
+    AC_CACHE_CHECK([if word-sized integers must be word-size aligned],
+        [ompi_cv_c_word_size_align],
+        [AC_LANG_PUSH(C)
+         AC_RUN_IFELSE([AC_LANG_PROGRAM([dnl
+#include <stdlib.h>], [[    long data[2] = {0, 0};
+    long *lp;
+    int *ip;
+    ip = (int*) data;
+    ip++;
+    lp = (long*) ip;
+    return lp[0]; ]])],
+            [ompi_cv_c_word_size_align=no],
+            [ompi_cv_c_word_size_align=yes],
+            [ompi_cv_c_word_size_align=yes])])
+fi
+AS_IF([test $ompi_cv_c_word_size_align = yes], [results=1], [results=0])
+AC_DEFINE_UNQUOTED([OPAL_ALIGN_WORD_SIZE_INTEGERS], [$results],
+    [set to 1 if word-size integers must be aligned to word-size padding to prevent bus errors])
+
 #
 # Check for other compiler characteristics
 #
@@ -651,6 +659,14 @@ AM_CONDITIONAL(OSHMEM_BUILD_FORTRAN_BINDINGS,
 AC_CACHE_SAVE
 
 
+##################################
+# Wrapper compilers.
+#
+# Must be called before MCA system
+##################################
+OPAL_SETUP_WRAPPER_INIT
+
+
 ##################################
 # Header files
 ##################################
@@ -904,7 +920,7 @@ OPAL_SEARCH_LIBS_CORE([ceil], [m])
 # -lrt might be needed for clock_gettime
 OPAL_SEARCH_LIBS_CORE([clock_gettime], [rt])
 
-AC_CHECK_FUNCS([asprintf snprintf vasprintf vsnprintf openpty isatty getpwuid fork waitpid execve pipe ptsname setsid mmap tcgetpgrp posix_memalign strsignal sysconf syslog vsyslog regcmp regexec regfree _NSGetEnviron socketpair usleep mkfifo dbopen dbm_open statfs statvfs setpgid setenv __malloc_initialize_hook __clear_cache])
+AC_CHECK_FUNCS([asprintf snprintf vasprintf vsnprintf openpty isatty getpwuid fork waitpid execve pipe ptsname setsid mmap tcgetpgrp posix_memalign strsignal sysconf syslog vsyslog regcmp regexec regfree _NSGetEnviron socketpair usleep mkfifo dbopen dbm_open statfs statvfs setpgid setenv __malloc_initialize_hook __clear_cache on_exit])
 
 # Sanity check: ensure that we got at least one of statfs or statvfs.
 if test $ac_cv_func_statfs = no && test $ac_cv_func_statvfs = no; then
@@ -963,6 +979,9 @@ AC_CACHE_SAVE
 
 opal_show_title "System-specific tests"
 
+OPAL_CHECK_CUDA
+OPAL_CHECK_OS_FLAVORS
+
 # Do we have _SC_NPROCESSORS_ONLN? (only going to pass if we also have
 # <unistd.h> and sysconf(), which is ok) OS X 10.4 has <unistd.h> and
 # sysconf(), but does not have _SC_NPROCESSORS_ONLN.  Doh!