diff --git a/core.py b/core.py
index 7916305..3a82f1c 100644
--- a/core.py
+++ b/core.py
@@ -21,7 +21,7 @@ def validate_input(ip, val_range):
         if ip in val_range:
             return ip
     except Exception:
-        pass
+        return None
     return None