diff --git a/configure b/configure
index 32efe7f27aa..baebf8836a1 100755
--- a/configure
+++ b/configure
@@ -12159,7 +12159,7 @@ fi
 $as_echo "$ac_cv_c_fortify_enabled" >&6; }
 if test "$ac_cv_c_fortify_enabled" = yes
 then
-    EXTRACFLAGS="$EXTRACFLAGS -D_FORTIFY_SOURCE=0"
+    CFLAGS="$CFLAGS -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=0"
 fi
 
 
diff --git a/configure.ac b/configure.ac
index 7b6818bb678..50feee408c0 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1690,7 +1690,7 @@ AC_CACHE_CHECK([for the need to disable Fortify], ac_cv_c_fortify_enabled,
         [ac_cv_c_fortify_enabled=no],[ac_cv_c_fortify_enabled=yes]))
 if test "$ac_cv_c_fortify_enabled" = yes
 then
-    EXTRACFLAGS="$EXTRACFLAGS -D_FORTIFY_SOURCE=0"
+    CFLAGS="$CFLAGS -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=0"
 fi
 
 dnl **** Check for underscore on external symbols ****