diff --git a/main.py b/main.py
index b26d01f..9585e67 100644
--- a/main.py
+++ b/main.py
@@ -92,7 +92,7 @@ def is_valid_prefix(prefix):
 
 def is_valid_asn(asn):
     # Check if the ASN is a string starting with "AS", followed by numbers or just a number
-    if type(asn) is int:
+    if asn.isdigit():
         return True
     if re.match(r'^[Aa][Ss]\d+$', asn):
         return True