diff --git a/firmware/ihex2fw.c b/firmware/ihex2fw.c
index 8f7fdaa9..5a03ba8 100644
--- a/firmware/ihex2fw.c
+++ b/firmware/ihex2fw.c
@@ -56,7 +56,7 @@
 static int sort_records = 0;
 static int wide_records = 0;
 
-int usage(void)
+static int usage(void)
 {
 	fprintf(stderr, "ihex2fw: Convert ihex files into binary "
 		"representation for use by Linux kernel\n");