diff --git a/spec/suites/layer/ImageOverlaySpec.js b/spec/suites/layer/ImageOverlaySpec.js
index 08b65a78..6f1616a8 100644
--- a/spec/suites/layer/ImageOverlaySpec.js
+++ b/spec/suites/layer/ImageOverlaySpec.js
@@ -168,6 +168,7 @@ describe('ImageOverlay', function () {
 		// https://html.spec.whatwg.org/multipage/urls-and-fetching.html#cors-settings-attributes
 		testCrossOriginValue(undefined, null); // Falsy value (other than empty string '') => no attribute set.
 		testCrossOriginValue(true, '');
+		testCrossOriginValue('', '');
 		testCrossOriginValue('anonymous', 'anonymous');
 		testCrossOriginValue('use-credentials', 'use-credentials');
 
diff --git a/spec/suites/layer/tile/TileLayerSpec.js b/spec/suites/layer/tile/TileLayerSpec.js
index 655c2320..2f1c032d 100644
--- a/spec/suites/layer/tile/TileLayerSpec.js
+++ b/spec/suites/layer/tile/TileLayerSpec.js
@@ -440,6 +440,7 @@ describe('TileLayer', function () {
 		// https://html.spec.whatwg.org/multipage/urls-and-fetching.html#cors-settings-attributes
 		testCrossOriginValue(undefined, null); // Falsy value (other than empty string '') => no attribute set.
 		testCrossOriginValue(true, '');
+		testCrossOriginValue('', '');
 		testCrossOriginValue('anonymous', 'anonymous');
 		testCrossOriginValue('use-credentials', 'use-credentials');