diff --git a/lib/galaxy/datatypes/registry.py b/lib/galaxy/datatypes/registry.py
index d0d0ab3c5d4..a72ae2d5bed 100644
--- a/lib/galaxy/datatypes/registry.py
+++ b/lib/galaxy/datatypes/registry.py
@@ -219,8 +219,6 @@ class Registry( object ):
             builder = self.datatypes_by_extension[ext]
         except KeyError:
             builder = data.Text()
-            if ext is not None:
-                self.log.warning('unknown extension in data factory %s', ext)
         return builder
 
     def change_datatype(self, data, ext ):