diff --git a/m4/virt-compile-warnings.m4 b/m4/virt-compile-warnings.m4
index f9460e82ba..411d257465 100644
--- a/m4/virt-compile-warnings.m4
+++ b/m4/virt-compile-warnings.m4
@@ -189,6 +189,11 @@ AC_DEFUN([LIBVIRT_COMPILE_WARNINGS],[
       wantwarn="$wantwarn -Werror"
     fi
 
+    # Request the gnu99 standard which is the best choice with
+    # gcc 4.8.0. Not a warning flag, but the probing mechanism
+    # is convenient
+    wantwarn="-std=gnu99"
+
     # Check for $CC support of each warning
     for w in $wantwarn; do
       gl_WARN_ADD([$w])