diff --git a/tests/php/Forms/HTMLEditor/TinyMCECombinedGeneratorTest.php b/tests/php/Forms/HTMLEditor/TinyMCECombinedGeneratorTest.php
index 69b832c74..76a4d31ca 100644
--- a/tests/php/Forms/HTMLEditor/TinyMCECombinedGeneratorTest.php
+++ b/tests/php/Forms/HTMLEditor/TinyMCECombinedGeneratorTest.php
@@ -54,11 +54,7 @@ class TinyMCECombinedGeneratorTest extends SapphireTest
         // Get config for this
         /** @var TinyMCECombinedGenerator $generator */
         $generator = Injector::inst()->create(TinyMCECombinedGenerator::class);
-        $this->assertEquals(
-            '_tinymce/tinymce-testconfig-6422b3814d.js',
-            $generator->generateFilename($c),
-            "Filename for config: " . json_encode($c->getAttributes()) . " should match expected value"
-        );
+        $this->assertRegExp('#_tinymce/tinymce-testconfig-[0-9a-z]{10,10}#', $generator->generateFilename($c));
         $content = $generator->generateContent($c);
         $this->assertContains(
             "var baseURL = baseTag.length ? baseTag[0].baseURI : 'http://www.mysite.com/basedir/';\n",