diff --git a/src/applications/differential/editor/DifferentialTransactionEditor.php b/src/applications/differential/editor/DifferentialTransactionEditor.php
--- a/src/applications/differential/editor/DifferentialTransactionEditor.php
+++ b/src/applications/differential/editor/DifferentialTransactionEditor.php
@@ -1276,6 +1276,8 @@
     }
 
     $edges = array();
+    $task_phids = array();
+    $rev_phids = array();
 
     if ($task_map) {
       $tasks = id(new ManiphestTaskQuery())
@@ -1284,10 +1286,9 @@
         ->execute();
 
       if ($tasks) {
-        $phid_map = mpull($tasks, 'getPHID', 'getPHID');
+        $task_phids = mpull($tasks, 'getPHID', 'getPHID');
         $edge_related = DifferentialRevisionHasTaskEdgeType::EDGECONST;
-        $edges[$edge_related] = $phid_map;
-        $this->setUnmentionablePHIDMap($phid_map);
+        $edges[$edge_related] = $task_phids;
       }
     }
 
@@ -1308,6 +1309,8 @@
       }
     }
 
+    $this->setUnmentionablePHIDMap(array_merge($task_phids, $rev_phids));
+
     $result = array();
     foreach ($edges as $type => $specs) {
       $result[] = id(new DifferentialTransaction())