diff --git a/lib/Db/AddMissingIndices.php b/lib/Db/AddMissingIndices.php
index 99d3d2da..98adabfa 100644
--- a/lib/Db/AddMissingIndices.php
+++ b/lib/Db/AddMissingIndices.php
@@ -17,6 +17,16 @@ class AddMissingIndices
         // Should migrate at end
         $shouldMigrate = false;
 
+        // Speed up CTE lookup for subdirectories
+        if ($schema->hasTable('filecache')) {
+            $table = $schema->getTable('filecache');
+
+            if (!$table->hasIndex('memories_parent_mimetype')) {
+                $table->addIndex(['parent', 'mimetype'], 'memories_parent_mimetype');
+                $shouldMigrate = true;
+            }
+        }
+
         // Add index on systemtag_object_mapping to speed up the query
         if ($schema->hasTable('systemtag_object_mapping')) {
             $table = $schema->getTable('systemtag_object_mapping');
diff --git a/lib/Migration/Version400308Date20221026151748.php b/lib/Migration/Version400308Date20221026151748.php
index ee680f96..5b5748d3 100644
--- a/lib/Migration/Version400308Date20221026151748.php
+++ b/lib/Migration/Version400308Date20221026151748.php
@@ -42,15 +42,9 @@ class Version400308Date20221026151748 extends SimpleMigrationStep
      */
     public function changeSchema(IOutput $output, \Closure $schemaClosure, array $options): ?ISchemaWrapper
     {
-        /** @var ISchemaWrapper $schema */
-        $schema = $schemaClosure();
-
-        // Speed up CTE lookup for subdirectories
-        $fileCacheTable = $schema->getTable('filecache');
-        $fileCacheTable->addIndex(['parent', 'mimetype'], 'memories_parent_mimetype');
-
-        // Add other indices
-        return $schema;
+        // Addition of memories_parent_mimetype moved to AddMissingIndices
+        // since this is on an external table (filecache)
+        return null;
     }
 
     /**