diff --git a/src/applications/audit/editor/PhabricatorAuditEditor.php b/src/applications/audit/editor/PhabricatorAuditEditor.php
--- a/src/applications/audit/editor/PhabricatorAuditEditor.php
+++ b/src/applications/audit/editor/PhabricatorAuditEditor.php
@@ -115,7 +115,6 @@
     PhabricatorApplicationTransaction $xaction) {
 
     switch ($xaction->getTransactionType()) {
-      case PhabricatorTransactions::TYPE_COMMENT:
       case PhabricatorAuditActionConstants::ACTION:
       case PhabricatorAuditActionConstants::INLINE:
       case PhabricatorAuditActionConstants::ADD_AUDITORS:
@@ -131,7 +130,6 @@
     PhabricatorApplicationTransaction $xaction) {
 
     switch ($xaction->getTransactionType()) {
-      case PhabricatorTransactions::TYPE_COMMENT:
       case PhabricatorAuditActionConstants::ACTION:
       case PhabricatorAuditTransaction::TYPE_COMMIT:
         return;
diff --git a/src/applications/calendar/editor/PhabricatorCalendarEventEditor.php b/src/applications/calendar/editor/PhabricatorCalendarEventEditor.php
--- a/src/applications/calendar/editor/PhabricatorCalendarEventEditor.php
+++ b/src/applications/calendar/editor/PhabricatorCalendarEventEditor.php
@@ -108,7 +108,6 @@
         $object->setIsAllDay((int)$xaction->getNewValue());
         return;
       case PhabricatorCalendarEventTransaction::TYPE_INVITE:
-      case PhabricatorTransactions::TYPE_COMMENT:
       case PhabricatorTransactions::TYPE_VIEW_POLICY:
       case PhabricatorTransactions::TYPE_EDIT_POLICY:
         return;
@@ -149,7 +148,6 @@
         }
         $object->attachInvitees($invitees);
         return;
-      case PhabricatorTransactions::TYPE_COMMENT:
       case PhabricatorTransactions::TYPE_VIEW_POLICY:
       case PhabricatorTransactions::TYPE_EDIT_POLICY:
         return;
diff --git a/src/applications/conpherence/editor/ConpherenceEditor.php b/src/applications/conpherence/editor/ConpherenceEditor.php
--- a/src/applications/conpherence/editor/ConpherenceEditor.php
+++ b/src/applications/conpherence/editor/ConpherenceEditor.php
@@ -247,9 +247,6 @@
 
     $make_author_recent_participant = true;
     switch ($xaction->getTransactionType()) {
-      case PhabricatorTransactions::TYPE_COMMENT:
-        $object->setMessageCount((int)$object->getMessageCount() + 1);
-        break;
       case ConpherenceTransactionType::TYPE_TITLE:
         $object->setTitle($xaction->getNewValue());
         break;
@@ -296,6 +293,19 @@
     }
   }
 
+  protected function applyBuiltinInternalTransaction(
+    PhabricatorLiskDAO $object,
+    PhabricatorApplicationTransaction $xaction) {
+
+    switch ($xaction->getTransactionType()) {
+      case PhabricatorTransactions::TYPE_COMMENT:
+        $object->setMessageCount((int)$object->getMessageCount() + 1);
+        break;
+    }
+
+    return parent::applyBuiltinInternalTransaction($object, $xaction);
+  }
+
   private function makeAuthorMostRecentParticipant(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
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
@@ -195,7 +195,6 @@
       case PhabricatorTransactions::TYPE_EDIT_POLICY:
         $object->setEditPolicy($xaction->getNewValue());
         return;
-      case PhabricatorTransactions::TYPE_COMMENT:
       case DifferentialTransaction::TYPE_INLINE:
         return;
       case DifferentialTransaction::TYPE_UPDATE:
@@ -577,7 +576,6 @@
       case PhabricatorTransactions::TYPE_VIEW_POLICY:
       case PhabricatorTransactions::TYPE_EDIT_POLICY:
         return;
-      case PhabricatorTransactions::TYPE_COMMENT:
       case DifferentialTransaction::TYPE_ACTION:
         return;
       case DifferentialTransaction::TYPE_INLINE:
diff --git a/src/applications/paste/editor/PhabricatorPasteEditor.php b/src/applications/paste/editor/PhabricatorPasteEditor.php
--- a/src/applications/paste/editor/PhabricatorPasteEditor.php
+++ b/src/applications/paste/editor/PhabricatorPasteEditor.php
@@ -88,8 +88,6 @@
       case PhabricatorTransactions::TYPE_EDIT_POLICY:
         $object->setEditPolicy($xaction->getNewValue());
         return;
-      case PhabricatorTransactions::TYPE_COMMENT:
-        return;
     }
 
     return parent::applyCustomInternalTransaction($object, $xaction);
@@ -105,7 +103,6 @@
       case PhabricatorPasteTransaction::TYPE_LANGUAGE:
       case PhabricatorTransactions::TYPE_VIEW_POLICY:
       case PhabricatorTransactions::TYPE_EDIT_POLICY:
-      case PhabricatorTransactions::TYPE_COMMENT:
         return;
     }
 
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
@@ -404,6 +404,7 @@
       case PhabricatorTransactions::TYPE_SUBSCRIBERS:
       case PhabricatorTransactions::TYPE_INLINESTATE:
       case PhabricatorTransactions::TYPE_EDGE:
+      case PhabricatorTransactions::TYPE_COMMENT:
         return $this->applyBuiltinInternalTransaction($object, $xaction);
     }
 
@@ -500,6 +501,7 @@
         $field = $this->getCustomFieldForTransaction($object, $xaction);
         return $field->applyApplicationTransactionExternalEffects($xaction);
       case PhabricatorTransactions::TYPE_INLINESTATE:
+      case PhabricatorTransactions::TYPE_COMMENT:
         return $this->applyBuiltinExternalTransaction($object, $xaction);
     }