diff --git a/cmd/optee.c b/cmd/optee.c
index d0d3729..e3aae5e 100644
--- a/cmd/optee.c
+++ b/cmd/optee.c
@@ -53,7 +53,7 @@
 {
 	int ret, value = 0;
 
-	if (strcmp(argv[1], NULL))
+	if (argc > 1)
 		value = hextoul(argv[1], NULL);
 
 	ret = hello_world_ta(value);