diff --git a/components/script/dom/webglrenderingcontext.rs b/components/script/dom/webglrenderingcontext.rs
index c44578bbaf1..32059db6302 100644
--- a/components/script/dom/webglrenderingcontext.rs
+++ b/components/script/dom/webglrenderingcontext.rs
@@ -1330,6 +1330,10 @@ impl WebGLRenderingContextMethods for WebGLRenderingContext {
                 let unpack = self.texture_unpacking_settings.get();
                 return BooleanValue(unpack.contains(TextureUnpacking::FLIP_Y_AXIS));
             }
+            constants::UNPACK_PREMULTIPLY_ALPHA_WEBGL => {
+                let unpack = self.texture_unpacking_settings.get();
+                return BooleanValue(unpack.contains(TextureUnpacking::PREMULTIPLY_ALPHA));
+            }
             _ => {}
         }
 
diff --git a/tests/wpt/mozilla/meta/webgl/conformance-1.0.3/conformance/state/gl-get-calls.html.ini b/tests/wpt/mozilla/meta/webgl/conformance-1.0.3/conformance/state/gl-get-calls.html.ini
index 11484fc0167..87558e7b05a 100644
--- a/tests/wpt/mozilla/meta/webgl/conformance-1.0.3/conformance/state/gl-get-calls.html.ini
+++ b/tests/wpt/mozilla/meta/webgl/conformance-1.0.3/conformance/state/gl-get-calls.html.ini
@@ -57,9 +57,6 @@
   [WebGL test #47: context.getParameter(context.SCISSOR_TEST) should be false (of type boolean). Was null (of type object).]
     expected: FAIL
 
-  [WebGL test #86: context.getParameter(context.UNPACK_PREMULTIPLY_ALPHA_WEBGL) should be false (of type boolean). Was null (of type object).]
-    expected: FAIL
-
   [WebGL test #88: context.getParameter(context.VIEWPORT) is not an instance of Int32Array]
     expected: FAIL