diff --git a/pre-upload.py b/pre-upload.py
index 6807c48..47a96d0 100755
--- a/pre-upload.py
+++ b/pre-upload.py
@@ -1940,7 +1940,8 @@
   disabled_hooks = set(hooks[x] for x in disable_flags)
 
   if _check_change_has_signoff_field not in enabled_hooks:
-    enabled_hooks.add(_check_change_has_no_signoff_field)
+    if _check_change_has_signoff_field not in disabled_hooks:
+      enabled_hooks.add(_check_change_has_no_signoff_field)
   if _check_change_has_branch_field not in enabled_hooks:
     enabled_hooks.add(_check_change_has_no_branch_field)