diff --git a/src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php b/src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php
--- a/src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php
+++ b/src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php
@@ -1677,6 +1677,9 @@
 
         // You need CAN_EDIT to change members other than yourself.
         return PhabricatorPolicyCapability::CAN_EDIT;
+      case PhabricatorObjectHasWatcherEdgeType::EDGECONST:
+        // See PHI1024. Watching a project does not require CAN_EDIT.
+        return null;
       default:
         return PhabricatorPolicyCapability::CAN_EDIT;
     }