diff --git a/gfx/webrender_bindings/src/bindings.rs b/gfx/webrender_bindings/src/bindings.rs
index 860e73fa1a42..b73de9a234b2 100644
--- a/gfx/webrender_bindings/src/bindings.rs
+++ b/gfx/webrender_bindings/src/bindings.rs
@@ -1258,7 +1258,7 @@ pub extern "C" fn wr_dp_push_stacking_context(state: &mut WrState,
             WrFilterOpType::Grayscale => FilterOp::Grayscale(c_filter.argument),
             WrFilterOpType::HueRotate => FilterOp::HueRotate(c_filter.argument),
             WrFilterOpType::Invert => FilterOp::Invert(c_filter.argument),
-            WrFilterOpType::Opacity => FilterOp::Opacity(PropertyBinding::Value(c_filter.argument)),
+            WrFilterOpType::Opacity => FilterOp::Opacity(PropertyBinding::Value(c_filter.argument), c_filter.argument),
             WrFilterOpType::Saturate => FilterOp::Saturate(c_filter.argument),
             WrFilterOpType::Sepia => FilterOp::Sepia(c_filter.argument),
         }
@@ -1267,7 +1267,7 @@ pub extern "C" fn wr_dp_push_stacking_context(state: &mut WrState,
     let opacity_ref = unsafe { opacity.as_ref() };
     if let Some(opacity) = opacity_ref {
         if *opacity < 1.0 {
-            filters.push(FilterOp::Opacity(PropertyBinding::Value(*opacity)));
+            filters.push(FilterOp::Opacity(PropertyBinding::Value(*opacity), *opacity));
         }
     }
 
@@ -1281,7 +1281,7 @@ pub extern "C" fn wr_dp_push_stacking_context(state: &mut WrState,
     if let Some(anim) = anim {
         debug_assert!(anim.id > 0);
         match anim.effect_type {
-            WrAnimationType::Opacity => filters.push(FilterOp::Opacity(PropertyBinding::Binding(PropertyBindingKey::new(anim.id)))),
+            WrAnimationType::Opacity => filters.push(FilterOp::Opacity(PropertyBinding::Binding(PropertyBindingKey::new(anim.id)), 1.0)),
             WrAnimationType::Transform => transform_binding = Some(PropertyBinding::Binding(PropertyBindingKey::new(anim.id))),
         }
     }