Index: kernel/Makefile
===================================================================
--- kernel/Makefile	(revision afdcc60e9cc75aa7bdedc29f54dc7ea32809d95c)
+++ kernel/Makefile	(revision 9f2de9253acdd441e502bbbb86a6091c8d9d30a2)
@@ -94,5 +94,5 @@
 	-fexec-charset=UTF-8 -fwide-exec-charset=UTF-32$(ENDIANESS) \
 	-finput-charset=UTF-8 -ffreestanding -fno-builtin -nostdlib -nostdinc \
-	-Wall -Wextra -Wno-unused-parameter -Wmissing-prototypes \
+	-std=gnu99 -Wall -Wextra -Wno-unused-parameter -Wmissing-prototypes \
 	-Werror-implicit-function-declaration -Wwrite-strings \
 	-pipe