diff -u b/modules/webform_ajax/tests/src/FunctionalJavascript/WebformAjaxTest.php b/modules/webform_ajax/tests/src/FunctionalJavascript/WebformAjaxTest.php
--- b/modules/webform_ajax/tests/src/FunctionalJavascript/WebformAjaxTest.php
+++ b/modules/webform_ajax/tests/src/FunctionalJavascript/WebformAjaxTest.php
@@ -169,7 +169,7 @@
 
     $this->assertNotNull($element, "An AJAX submission redirects to a custom URL.");
     $assert->pageTextContains('test value');
-    $this->assertEquals($actual_path, '/');
+    $this->assertEquals($actual_path, base_path());
   }
 
   /**
@@ -190,7 +190,7 @@
     $this->assertNotNull($element, "An AJAX submission redirects to a custom URL.");
     $assert->pageTextContains('New submission added to Test webform');
     $assert->pageTextContains('test value');
-    $this->assertEquals($actual_path, '/');
+    $this->assertEquals($actual_path, base_path());
   }
 
   /**