diff --git a/utils/nfc-mfultralight.c b/utils/nfc-mfultralight.c
index 3fe2100..8c6859a 100644
--- a/utils/nfc-mfultralight.c
+++ b/utils/nfc-mfultralight.c
@@ -290,7 +290,7 @@ unlock_card(void)
   return true;
 }
 
-static bool check_magic()
+static bool check_magic(void)
 {
   bool     bFailure = false;
   int      uid_data;