diff --git a/tests/amp_url_formats.test b/tests/amp_url_formats.test
index 119d043..3f3c9cf 100644
--- a/tests/amp_url_formats.test
+++ b/tests/amp_url_formats.test
@@ -38,6 +38,9 @@ class AmpTestUrlFormats extends DrupalWebTestCase {
     // checkout amptheme.
     theme_enable(array('amptheme', 'ampsubtheme_example'));
 
+    // Enable Clean urls.
+    variable_set('clean_url', TRUE);
+
     // Enable AMP display on article content.
     $this->drupalGet("admin/structure/types/manage/article/display");
     $this->assertResponse(200);