diff --git a/disas/nanomips.c b/disas/nanomips.c
index e4b21e7c45..3f45447292 100644
--- a/disas/nanomips.c
+++ b/disas/nanomips.c
@@ -95,7 +95,7 @@ typedef struct Pool {
 #define IMGASSERTONCE(test)
 
 
-static char *img_format(const char *format, ...)
+static char * G_GNUC_PRINTF(1, 2) img_format(const char *format, ...)
 {
     char *buffer;
     va_list args;