diff --git a/src/main.cpp b/src/main.cpp
index 13dbb0a677869a12ffec3fa1900d12b4013c98ae..48e605faa108d13db4258385846c26c2e2ca2e7b 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -17,7 +17,7 @@ int clamp(int n, int lower, int upper) {
 int main(int argc, char** args) {
 
     //Check args
-    if (argc == 0) {
+    if (argc < 2) {
         printf("USAGE: medianfilter lena_gray.bmp\n");
         return 0;
     }