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
@@ -1531,7 +1531,10 @@
     $path_prefix = null;
 
     $local_root = $diff->getSourceControlPath();
-    if ($local_root) {
+    $is_svn = $repository->getVersionControlSystem() ==
+      PhabricatorRepositoryType::REPOSITORY_TYPE_SVN;
+
+    if ($local_root && $is_svn) {
       // We're in a working copy which supports subdirectory checkouts (e.g.,
       // SVN) so we need to figure out what prefix we should add to each path
       // (e.g., trunk/projects/example/) to get the absolute path from the