diff --git a/components/style/properties/helpers/animated_properties.mako.rs b/components/style/properties/helpers/animated_properties.mako.rs
index 759ba8ae0bb..7a62561a8e1 100644
--- a/components/style/properties/helpers/animated_properties.mako.rs
+++ b/components/style/properties/helpers/animated_properties.mako.rs
@@ -46,7 +46,7 @@ use values::animated::effects::Filter as AnimatedFilter;
 use values::animated::effects::FilterList as AnimatedFilterList;
 use values::animated::effects::TextShadowList as AnimatedTextShadowList;
 use values::computed::{Angle, BorderCornerRadius, CalcLengthOrPercentage};
-use values::computed::{ClipRect, Context, ComputedUrl, ComputedValueAsSpecified};
+use values::computed::{ClipRect, Context, ComputedUrl};
 use values::computed::{LengthOrPercentage, LengthOrPercentageOrAuto};
 use values::computed::{LengthOrPercentageOrNone, MaxLength, NonNegativeAu};
 use values::computed::{NonNegativeNumber, Number, NumberOrPercentage, Percentage};
@@ -203,7 +203,7 @@ pub fn nscsspropertyid_is_animatable(property: nsCSSPropertyID) -> bool {
 // NB: This needs to be here because it needs all the longhands generated
 // beforehand.
 #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
-#[derive(Clone, Debug, Eq, Hash, PartialEq, ToCss)]
+#[derive(Clone, Debug, Eq, Hash, PartialEq, ToCss, ToComputedValue)]
 pub enum TransitionProperty {
     /// All, any transitionable property changing should generate a transition.
     All,
@@ -218,9 +218,6 @@ pub enum TransitionProperty {
     Unsupported(CustomIdent)
 }
 
-
-impl ComputedValueAsSpecified for TransitionProperty {}
-
 impl TransitionProperty {
     /// Iterates over each longhand property.
     pub fn each<F: FnMut(&TransitionProperty) -> ()>(mut cb: F) {