diff --git a/client/cmdhfmf.c b/client/cmdhfmf.c
index abc88b862..e5592efa4 100644
--- a/client/cmdhfmf.c
+++ b/client/cmdhfmf.c
@@ -988,6 +988,7 @@ int CmdHF14AMfChk(const char *Cmd)
 		break;
 	default:
 		PrintAndLog("Key type must be A , B or ?");
+		free(keyBlock);
 		return 1;
 	};