diff --git a/src/applications/conpherence/controller/ConpherenceListController.php b/src/applications/conpherence/controller/ConpherenceListController.php
index 80ef89d66a..916d044e86 100644
--- a/src/applications/conpherence/controller/ConpherenceListController.php
+++ b/src/applications/conpherence/controller/ConpherenceListController.php
@@ -41,11 +41,7 @@ final class ConpherenceListController extends
       }
       $this->setSelectedConpherencePHID($conpherence->getPHID());
 
-      $read_status =  ConpherenceParticipationStatus::UP_TO_DATE;
       $participant = $conpherence->getParticipant($user->getPHID());
-      $write_guard = AphrontWriteGuard::beginScopedUnguardedWrites();
-      $participant->markUpToDate();
-      unset($write_guard);
       $current_selection_epoch = $participant->getDateTouched();
     }
 
diff --git a/src/applications/conpherence/controller/ConpherenceViewController.php b/src/applications/conpherence/controller/ConpherenceViewController.php
index 284d237802..d615edac50 100644
--- a/src/applications/conpherence/controller/ConpherenceViewController.php
+++ b/src/applications/conpherence/controller/ConpherenceViewController.php
@@ -49,8 +49,10 @@ final class ConpherenceViewController extends
     $this->setConpherence($conpherence);
 
     $participant = $conpherence->getParticipant($user->getPHID());
+    $transactions = $conpherence->getTransactions();
+    $latest_transaction = end($transactions);
     $write_guard = AphrontWriteGuard::beginScopedUnguardedWrites();
-    $participant->markUpToDate();
+    $participant->markUpToDate($latest_transaction);
     unset($write_guard);
 
     $header = $this->renderHeaderPaneContent();
diff --git a/src/applications/conpherence/storage/ConpherenceParticipant.php b/src/applications/conpherence/storage/ConpherenceParticipant.php
index e21d6204ad..be897c11fe 100644
--- a/src/applications/conpherence/storage/ConpherenceParticipant.php
+++ b/src/applications/conpherence/storage/ConpherenceParticipant.php
@@ -11,9 +11,10 @@ final class ConpherenceParticipant extends ConpherenceDAO {
   protected $behindTransactionPHID;
   protected $dateTouched;
 
-  public function markUpToDate() {
+  public function markUpToDate(ConpherenceTransaction $xaction) {
     if (!$this->isUpToDate()) {
       $this->setParticipationStatus(ConpherenceParticipationStatus::UP_TO_DATE);
+      $this->setBehindTransactionPHID($xaction->getPHID());
       $this->save();
     }
     return $this;
diff --git a/src/applications/conpherence/storage/ConpherenceThread.php b/src/applications/conpherence/storage/ConpherenceThread.php
index c5c2c4723a..1b80aec1a5 100644
--- a/src/applications/conpherence/storage/ConpherenceThread.php
+++ b/src/applications/conpherence/storage/ConpherenceThread.php
@@ -189,15 +189,18 @@ final class ConpherenceThread extends ConpherenceDAO
           }
           // fallthrough intentionally here
         case ConpherenceTransactionType::TYPE_FILES:
-        default:
-          if ($behind_transaction_phid &&
-            $transaction->getPHID() != $behind_transaction_phid) {
-              $unread_count++;
+          if ($behind_transaction_phid) {
+            $unread_count++;
+            if ($transaction->getPHID() == $behind_transaction_phid) {
+              break 2;
             }
+          }
           if ($unread_count > $max_count) {
             break 2;
           }
           break;
+        default:
+          continue 2;
       }
       if ($snippet && !$behind_transaction_phid) {
         break;