diff --git a/core/modules/block_content/src/Tests/BlockContentCreationTest.php b/core/modules/block_content/src/Tests/BlockContentCreationTest.php
index 52b8d95..6edfdc3 100644
--- a/core/modules/block_content/src/Tests/BlockContentCreationTest.php
+++ b/core/modules/block_content/src/Tests/BlockContentCreationTest.php
@@ -112,7 +112,7 @@ public function testBlockContentCreationMultipleViewModes() {
     )), 'Basic block created.');
 
     // Save our block permanently
-    $this->drupalPostForm(NULL, NULL, t('Save block'));
+    $this->drupalPostForm(NULL, ['region' => 'content'], t('Save block'));
 
     // Set test_view_mode as a custom display to be available on the list.
     $this->drupalGet('admin/structure/block/block-content');