diff --git a/src/applications/diffusion/controller/DiffusionBrowseController.php b/src/applications/diffusion/controller/DiffusionBrowseController.php
--- a/src/applications/diffusion/controller/DiffusionBrowseController.php
+++ b/src/applications/diffusion/controller/DiffusionBrowseController.php
@@ -976,7 +976,8 @@
       $commit_identifier = $commit->getCommitIdentifier();
 
       $author_phid = '';
-      if (isset($revision_map[$commit_identifier])) {
+      if (isset($revision_map[$commit_identifier]) &&
+          isset($revisions[$revision_map[$commit_identifier]])) {
         $revision_id = $revision_map[$commit_identifier];
         $revision = $revisions[$revision_id];
         $author_phid = $revision->getAuthorPHID();