diff --git a/src/nip.py b/src/nip.py
index d7e2208..4a4e1d8 100755
--- a/src/nip.py
+++ b/src/nip.py
@@ -131,7 +131,7 @@ class DynamicBackend:
 
     def handle_subdomains(self, qname):
         subdomain = qname[0:qname.find(self.domain) - 1]
-        match = re.findall('^(?:.+\.)?(\d{1,3}([-.])\d{1,3}\2\d{1,3}\2\d{1,3})$', subdomain)
+        match = re.findall('^(?:.+\.)?(\d{1,3}[-.]\d{1,3}[-.]\d{1,3}[-.]\d{1,3})$', subdomain)
 
         if not match:
             if DEBUG: