diff --git a/manifests/mta.pp b/manifests/mta.pp
index bb3e5c191e4518b098ce753540e52a11411d08fb..5830a12eccfe78a349cf811645d1d17f4790580f 100644
--- a/manifests/mta.pp
+++ b/manifests/mta.pp
@@ -38,7 +38,7 @@ class postfix::mta {
   }
 
   $mynetworks = $postfix::mynetworks ? {
-    undef   => '127.0.0.1/8',
+    undef   => '127.0.0.0/8',
     default => $postfix::mynetworks,
   }