diff --git a/build.sh b/build.sh
index d709949..fee8f45 100755
--- a/build.sh
+++ b/build.sh
@@ -13,6 +13,6 @@ echo $CONFIG_ARGS
 (
   cd ${NGINX_PATH} || exit
   bash -c "./configure ${CONFIG_ARGS}"
-  make modules -j "$(nproc)"
+  CFLAGS=-std=c99 make modules -j "$(nproc)"
 )