diff --git a/components/canvas_traits/lib.rs b/components/canvas_traits/lib.rs
index 3682d252338..db945750a0c 100644
--- a/components/canvas_traits/lib.rs
+++ b/components/canvas_traits/lib.rs
@@ -74,7 +74,6 @@ pub enum FromLayoutMsg {
 }
 
 #[derive(Clone, Deserialize, Serialize)]
-#[serde(bound = "")] // Prevent serde from generating cyclic bounds.
 pub enum Canvas2dMsg {
     Arc(Point2D<f32>, f32, f32, f32, bool),
     ArcTo(Point2D<f32>, Point2D<f32>, f32),
diff --git a/components/gfx/display_list/mod.rs b/components/gfx/display_list/mod.rs
index 0e16da27133..17f9be5b485 100644
--- a/components/gfx/display_list/mod.rs
+++ b/components/gfx/display_list/mod.rs
@@ -791,7 +791,6 @@ impl fmt::Debug for StackingContext {
 
 /// One drawing command in the list.
 #[derive(Clone, Deserialize, HeapSizeOf, Serialize)]
-#[serde(bound = "")] // Prevent serde from generating cyclic bounds.
 pub enum DisplayItem {
     SolidColorClass(Box<SolidColorDisplayItem>),
     TextClass(Box<TextDisplayItem>),
diff --git a/components/script_traits/script_msg.rs b/components/script_traits/script_msg.rs
index c39aec161da..d183336f6f8 100644
--- a/components/script_traits/script_msg.rs
+++ b/components/script_traits/script_msg.rs
@@ -59,7 +59,6 @@ pub enum LogEntry {
 
 /// Messages from the script to the constellation.
 #[derive(Deserialize, Serialize)]
-#[serde(bound = "")] // Prevent serde from generating cyclic bounds.
 pub enum ScriptMsg {
     /// Indicates whether this pipeline is currently running animations.
     ChangeRunningAnimationsState(PipelineId, AnimationState),