diff --git a/src/httpaste/model/paste.py b/src/httpaste/model/paste.py
index 3e030ef..534f9a8 100755
--- a/src/httpaste/model/paste.py
+++ b/src/httpaste/model/paste.py
@@ -94,7 +94,7 @@ def load(proto: Paste, backend: object) -> Optional[Paste]:
     if proto.sub and model.sub != shash(
             proto.sub,
             model.data_hash,
-            proto.pid) or not proto.sub and model.sub:
+            proto.pid) or (not proto.sub and model.sub):
 
         raise SubError('Paste not owned by user')