diff --git a/core/includes/install.core.inc b/core/includes/install.core.inc
index 728f604..02a7a47 100644
--- a/core/includes/install.core.inc
+++ b/core/includes/install.core.inc
@@ -562,7 +562,8 @@ function install_run_task($task, &$install_state) {
         // there is nothing more to do here.
         return;
       }
-      if (!is_array($batches)) {
+      // Simulate a one item list of batches if only one batch was provided.
+      if (isset($batches['operations'])) {
         $batches = array($batches);
       }
       foreach ($batches as $batch) {