diff --git a/ex10.c b/ex10.c
index c06d77b..7cf8284 100644
--- a/ex10.c
+++ b/ex10.c
@@ -3,9 +3,10 @@
 int main(int argc, char *argv[])
 {
     int i = 0;
+    char *arg;
 
-    for(i = 0; i < argc; i++) {
-        printf("arg %d: %s\n", i, argv[i]);
+    for(i = 0; i < argc && (arg = argv[i]); i++) {
+        printf("arg %d: %s\n", i, arg);
     }
 
     char *states[] = {