--- a/testing/web-platform/meta/presentation-api/controlling-ua/PresentationRequest_error.html.ini
+++ b/testing/web-platform/meta/presentation-api/controlling-ua/PresentationRequest_error.html.ini
@@ -1,20 +1,6 @@
 [PresentationRequest_error.html]
   type: testharness
-  [Call PresentationRequest() constructor without presentation URL. TypeError Exception expected.]
-    expected: FAIL
-
-  [Call PresentationRequest() constructor with null presentation URL. TypeError Exception expected.]
-    expected: FAIL
-
-  [Call PresentationRequest constructor with null presentation URL. TypeError Exception expected.]
-    expected: FAIL
-
-  [Call PresentationRequest constructor with an empty sequence. NotSupportedError Exception expected.]
-    expected: FAIL
-
-  [Call PresentationRequest constructor with an invalid URL. SyntaxError Exception expected.]
-    expected: FAIL
-
-  [Call PresentationRequest constructor with a sequence of URLs, one of them invalid. SyntaxError Exception expected.]
-    expected: FAIL
-
+  prefs: [dom.presentation.enabled: true,
+          dom.presentation.controller.enabled: true,
+          dom.presentation.discovery.enabled: true,
+          dom.presentation.device.name: "Firefox"]

--- a/testing/web-platform/tests/presentation-api/controlling-ua/PresentationRequest_error.html
+++ b/testing/web-platform/tests/presentation-api/controlling-ua/PresentationRequest_error.html
@@ -9,31 +9,25 @@
 
     test(function() {
         assert_throws(new TypeError(), function() {
             new PresentationRequest();
         });
     }, 'Call PresentationRequest() constructor without presentation URL. TypeError Exception expected.');
 
     test(function() {
-        assert_throws(new TypeError(), function() {
-            new PresentationRequest(null);
-        });
-    }, 'Call PresentationRequest constructor with null presentation URL. TypeError Exception expected.');
-
-    test(function() {
         assert_throws('NotSupportedError', function() {
             new PresentationRequest([]);
         });
     }, 'Call PresentationRequest constructor with an empty sequence. NotSupportedError Exception expected.');
 
     test(function() {
         assert_throws('SyntaxError', function() {
-            new PresentationRequest(':invalid');
+            new PresentationRequest('http://@');
         });
     }, 'Call PresentationRequest constructor with an invalid URL. SyntaxError Exception expected.');
 
     test(function() {
         assert_throws('SyntaxError', function() {
-            new PresentationRequest(['presentation.html', ':invalid']);
+            new PresentationRequest(['presentation.html', 'http://@']);
         });
     }, 'Call PresentationRequest constructor with a sequence of URLs, one of them invalid. SyntaxError Exception expected.');
-</script>
\ No newline at end of file
+</script>