diff --git a/utils/nfc-mfclassic.c b/utils/nfc-mfclassic.c
index e019ddc..6530224 100644
--- a/utils/nfc-mfclassic.c
+++ b/utils/nfc-mfclassic.c
@@ -620,7 +620,7 @@ print_usage(const char *pcProgramName)
 }
 
 
-bool is_directwrite(void)
+static bool is_directwrite(void)
 {
   printf("Checking if Badge is DirectWrite...\n");