diff --git a/src/applications/differential/customfield/DifferentialManiphestTasksField.php b/src/applications/differential/customfield/DifferentialManiphestTasksField.php
--- a/src/applications/differential/customfield/DifferentialManiphestTasksField.php
+++ b/src/applications/differential/customfield/DifferentialManiphestTasksField.php
@@ -7,10 +7,6 @@
     return 'differential:maniphest-tasks';
   }
 
-  public function getFieldKeyForConduit() {
-    return 'maniphestTaskPHIDs';
-  }
-
   public function canDisableField() {
     return false;
   }
@@ -41,25 +37,6 @@
       DifferentialRevisionHasTaskEdgeType::EDGECONST);
   }
 
-  public function getApplicationTransactionType() {
-    return PhabricatorTransactions::TYPE_EDGE;
-  }
-
-  public function getApplicationTransactionMetadata() {
-    return array(
-      'edge:type' => DifferentialRevisionHasTaskEdgeType::EDGECONST,
-    );
-  }
-
-  public function getNewValueForApplicationTransactions() {
-    $edges = array();
-    foreach ($this->getValue() as $phid) {
-      $edges[$phid] = $phid;
-    }
-
-    return array('=' => $edges);
-  }
-
   public function getRequiredHandlePHIDsForPropertyView() {
     return $this->getValue();
   }
@@ -68,44 +45,4 @@
     return $this->renderHandleList($handles);
   }
 
-  public function shouldAppearInCommitMessage() {
-    return true;
-  }
-
-  public function shouldAllowEditInCommitMessage() {
-    return true;
-  }
-
-  public function getCommitMessageLabels() {
-    return array(
-      'Maniphest Task',
-      'Maniphest Tasks',
-    );
-  }
-
-  public function parseValueFromCommitMessage($value) {
-    return $this->parseObjectList(
-      $value,
-      array(
-        ManiphestTaskPHIDType::TYPECONST,
-      ));
-  }
-
-  public function getRequiredHandlePHIDsForCommitMessage() {
-    return $this->getRequiredHandlePHIDsForPropertyView();
-  }
-
-  public function renderCommitMessageValue(array $handles) {
-    return $this->renderObjectList($handles);
-  }
-
-  public function getProTips() {
-    return array(
-      pht(
-        'Write "%s" in your summary to automatically close the '.
-        'corresponding task when this change lands.',
-        'Fixes T123'),
-    );
-  }
-
 }
diff --git a/src/applications/differential/customfield/DifferentialProjectReviewersField.php b/src/applications/differential/customfield/DifferentialProjectReviewersField.php
--- a/src/applications/differential/customfield/DifferentialProjectReviewersField.php
+++ b/src/applications/differential/customfield/DifferentialProjectReviewersField.php
@@ -57,13 +57,4 @@
     return $reviewers;
   }
 
-  public function getProTips() {
-    return array(
-      pht(
-        'You can add a project as a subscriber or reviewer by writing '.
-        '"%s" in the appropriate field.',
-        '#projectname'),
-    );
-  }
-
 }
diff --git a/src/applications/differential/editor/DifferentialRevisionEditEngine.php b/src/applications/differential/editor/DifferentialRevisionEditEngine.php
--- a/src/applications/differential/editor/DifferentialRevisionEditEngine.php
+++ b/src/applications/differential/editor/DifferentialRevisionEditEngine.php
@@ -192,6 +192,21 @@
       ->setConduitTypeDescription(pht('New repository.'))
       ->setSingleValue($object->getRepositoryPHID());
 
+    // This is a little flimsy, but allows "Maniphest Tasks: ..." to continue
+    // working properly in commit messages until we fully sort out T5873.
+    $fields[] = id(new PhabricatorHandlesEditField())
+      ->setKey('tasks')
+      ->setUseEdgeTransactions(true)
+      ->setIsConduitOnly(true)
+      ->setTransactionType(PhabricatorTransactions::TYPE_EDGE)
+      ->setMetadataValue(
+        'edge:type',
+        DifferentialRevisionHasTaskEdgeType::EDGECONST)
+      ->setDescription(pht('Tasks associated with this revision.'))
+      ->setConduitDescription(pht('Change associated tasks.'))
+      ->setConduitTypeDescription(pht('List of tasks.'))
+      ->setValue(array());
+
     return $fields;
   }
 
diff --git a/src/applications/differential/field/DifferentialCommitMessageField.php b/src/applications/differential/field/DifferentialCommitMessageField.php
--- a/src/applications/differential/field/DifferentialCommitMessageField.php
+++ b/src/applications/differential/field/DifferentialCommitMessageField.php
@@ -182,7 +182,7 @@
   protected function isCustomFieldEnabled($key) {
     $field_list = PhabricatorCustomField::getObjectFields(
       new DifferentialRevision(),
-      DifferentialCustomField::ROLE_COMMITMESSAGE);
+      DifferentialCustomField::ROLE_DEFAULT);
 
     $fields = $field_list->getFields();
     return isset($fields[$key]);
diff --git a/src/applications/differential/field/DifferentialTasksCommitMessageField.php b/src/applications/differential/field/DifferentialTasksCommitMessageField.php
--- a/src/applications/differential/field/DifferentialTasksCommitMessageField.php
+++ b/src/applications/differential/field/DifferentialTasksCommitMessageField.php
@@ -55,7 +55,11 @@
   }
 
   public function getFieldTransactions($value) {
-    // TODO: Implement this!
-    return array();
+    return array(
+      array(
+        'type' => 'tasks.set',
+        'value' => $value,
+      ),
+    );
   }
 }