diff --git a/Zend/Zend.m4 b/Zend/Zend.m4
index 2c801c34e0572..c4e6086d0f7ff 100644
--- a/Zend/Zend.m4
+++ b/Zend/Zend.m4
@@ -190,7 +190,7 @@ AX_CHECK_COMPILE_FLAG([-Wformat-truncation], CFLAGS="-Wformat-truncation $CFLAGS
 AX_CHECK_COMPILE_FLAG([-Wstrict-prototypes], CFLAGS="-Wstrict-prototypes $CFLAGS", , [-Werror])
 AX_CHECK_COMPILE_FLAG([-fno-common], CFLAGS="-fno-common $CFLAGS", , [-Werror])
 
-test -n "$DEBUG_CFLAGS" && CFLAGS="$CFLAGS $DEBUG_CFLAGS"
+AS_VAR_IF([DEBUG_CFLAGS],,, [AS_VAR_APPEND([CFLAGS], [" $DEBUG_CFLAGS"])])
 
 if test "$ZEND_ZTS" = "yes"; then
   AC_DEFINE(ZTS,1,[ ])
diff --git a/configure.ac b/configure.ac
index eee1e3a60fddc..5374a179deb37 100644
--- a/configure.ac
+++ b/configure.ac
@@ -938,8 +938,6 @@ if test "$PHP_CONFIG_FILE_SCAN_DIR" = "DEFAULT"; then
 fi
 AC_MSG_RESULT([$PHP_CONFIG_FILE_SCAN_DIR])
 
-test -n "$DEBUG_CFLAGS" && CFLAGS="$CFLAGS $DEBUG_CFLAGS"
-
 PHP_ARG_ENABLE([sigchild],
   [whether to enable PHP's own SIGCHLD handler],
   [AS_HELP_STRING([--enable-sigchild],