diff --git a/configure.ac b/configure.ac
index 6962261..eb35f57 100644
--- a/configure.ac
+++ b/configure.ac
@@ -13,6 +13,8 @@
 RELMAKE='-include osmo-release.mk'
 AC_SUBST([RELMAKE])
 
+CFLAGS="$CFLAGS -std=gnu11"
+
 dnl kernel style compile messages
 m4_ifdef([AM_SILENT_RULES], [AM_SILENT_RULES([yes])])