diff --git a/mixbox/namespaces.py b/mixbox/namespaces.py
index <HASH>..<HASH> 100644
--- a/mixbox/namespaces.py
+++ b/mixbox/namespaces.py
@@ -317,6 +317,8 @@ class NamespaceSet(object):
             return
         elif not ni.schema_location:
             ni.schema_location = incoming_schemaloc or None
+        elif not incoming_schemaloc:
+            return
         else:
             raise ConflictingSchemaLocationError(ni.uri, ni.schema_location, incoming_schemaloc)
Fixed __merge_schema_locations() bug where exception was raised when existing NamespaceInfo has a schemaloc and input schemaloc is None. This condition is now a no-op.