diff --git a/spec/index.html b/spec/index.html
index f3898e00..9d9aa9a5 100644
--- a/spec/index.html
+++ b/spec/index.html
@@ -58,6 +58,7 @@
 	<!-- /layer -->
 	<script type="text/javascript" src="suites/layer/FeatureGroupSpec.js"></script>
 	<script type="text/javascript" src="suites/layer/GeoJSONSpec.js"></script>
+	<script type="text/javascript" src="suites/layer/ImageOverlaySpec.js"></script>
 	<script type="text/javascript" src="suites/layer/LayerGroupSpec.js"></script>
 	<script type="text/javascript" src="suites/layer/PopupSpec.js"></script>
 
diff --git a/spec/suites/layer/ImageOverlaySpec.js b/spec/suites/layer/ImageOverlaySpec.js
new file mode 100644
index 00000000..a3befa57
--- /dev/null
+++ b/spec/suites/layer/ImageOverlaySpec.js
@@ -0,0 +1,8 @@
+describe('ImageOverlay', function () {
+	describe('#setStyle', function () {
+		it('sets opacity', function () {
+			var overlay = L.imageOverlay().setStyle({opacity: 0.5});
+			expect(overlay.options.opacity).to.equal(0.5);
+		});
+	});
+});