diff --git a/glib/tests/mem-overflow.c b/glib/tests/mem-overflow.c
index 5e5dd68c0..64ec0b0cd 100644
--- a/glib/tests/mem-overflow.c
+++ b/glib/tests/mem-overflow.c
@@ -21,7 +21,7 @@
 
 /* We test for errors in optimize-only definitions in gmem.h */
 
-#ifdef __GNUC__
+#if defined(__GNUC__) && __GNUC__ > 6
 #pragma GCC optimize (1)
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Walloc-size-larger-than="