diff --git a/core/modules/migrate/tests/src/MigrateExecutableTest.php b/core/modules/migrate/tests/src/MigrateExecutableTest.php
index 6dcdea6..01e084c 100644
--- a/core/modules/migrate/tests/src/MigrateExecutableTest.php
+++ b/core/modules/migrate/tests/src/MigrateExecutableTest.php
@@ -569,10 +569,7 @@ public function testProcessRowEmptyPipeline() {
    */
   protected function getMockSource($valid_rows = 1) {
     $iterator = $this->getMock('\Iterator');
-    $return_values = array();
-    for ($i = 0; $i < $valid_rows; $i++) {
-      $return_values[] = TRUE;
-    }
+    $return_values = array_fill(0, $valid_rows, TRUE);
     $return_values[] = FALSE;
 
     $source = $this->getMockBuilder('Drupal\migrate\Source')