diff -u b/core/modules/migrate/tests/src/Unit/MigrateSqlIdMapTest.php b/core/modules/migrate/tests/src/Unit/MigrateSqlIdMapTest.php
--- b/core/modules/migrate/tests/src/Unit/MigrateSqlIdMapTest.php
+++ b/core/modules/migrate/tests/src/Unit/MigrateSqlIdMapTest.php
@@ -649,9 +649,15 @@
       [1, 101],
       [2, 102],
       [3, 103],
+      // Mock a failed row by setting the destination ID to NULL.
+      [4, NULL],
     ]);
 
+    // The rows are ordered by destination ID so the failed row should be first.
     $id_map->rewind();
+    $this->assertEquals([], $id_map->currentDestination());
+    $this->assertEquals(['nid' => 4], $id_map->currentSource());
+    $id_map->next();
     $this->assertEquals(['nid' => 101], $id_map->currentDestination());
     $this->assertEquals(['nid' => 1], $id_map->currentSource());
     $id_map->next();
@@ -660,6 +666,7 @@
     $id_map->next();
     $this->assertEquals(['nid' => 103], $id_map->currentDestination());
     $this->assertEquals(['nid' => 3], $id_map->currentSource());
+    $id_map->next();
   }
 
   /**