--- a/gfx/webrender_bindings/src/bindings.rs
+++ b/gfx/webrender_bindings/src/bindings.rs
@@ -1253,40 +1253,40 @@ pub extern "C" fn wr_dp_push_stacking_co
     let mut filters : Vec<FilterOp> = c_filters.iter().map(|c_filter| {
         match c_filter.filter_type {
             WrFilterOpType::Blur => FilterOp::Blur(c_filter.argument),
             WrFilterOpType::Brightness => FilterOp::Brightness(c_filter.argument),
             WrFilterOpType::Contrast => FilterOp::Contrast(c_filter.argument),
             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),
         }
     }).collect();
 
     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));
         }
     }
 
     let transform_ref = unsafe { transform.as_ref() };
     let mut transform_binding = match transform_ref {
         Some(transform) => Some(PropertyBinding::Value(transform.clone())),
         None => None,
     };
 
     let anim = unsafe { animation.as_ref() };
     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))),
         }
     }
 
     let perspective_ref = unsafe { perspective.as_ref() };
     let perspective = match perspective_ref {
         Some(perspective) => Some(perspective.clone()),
         None => None,