diff --git a/src/rect.rs b/src/rect.rs
index 9cd8942..8a87470 100644
--- a/src/rect.rs
+++ b/src/rect.rs
@@ -17,7 +17,7 @@ use std::cmp::PartialOrd;
 use std::fmt;
 use std::ops::{Add, Sub, Mul, Div};
 
-#[derive(Clone, Copy, RustcDecodable, RustcEncodable, PartialEq)]
+#[derive(Clone, Copy, Eq, RustcDecodable, RustcEncodable, PartialEq)]
 #[cfg_attr(feature = "plugins", derive(HeapSizeOf, Deserialize, Serialize))]
 pub struct Rect<T> {
     pub origin: Point2D<T>,
diff --git a/src/side_offsets.rs b/src/side_offsets.rs
index 7a71239..0b2c599 100644
--- a/src/side_offsets.rs
+++ b/src/side_offsets.rs
@@ -15,7 +15,7 @@ use std::ops::Add;
 
 /// A group of side offsets, which correspond to top/left/bottom/right for borders, padding,
 /// and margins in CSS.
-#[derive(Clone, Copy, PartialEq, Debug)]
+#[derive(Clone, Copy, Eq, PartialEq, Debug)]
 #[cfg_attr(feature = "plugins", derive(HeapSizeOf, Deserialize, Serialize))]
 pub struct SideOffsets2D<T> {
     pub top: T,
diff --git a/src/size.rs b/src/size.rs
index f2a627f..94a26c4 100644
--- a/src/size.rs
+++ b/src/size.rs
@@ -14,7 +14,7 @@ use num_lib::NumCast;
 use std::fmt;
 use std::ops::{Mul, Div};
 
-#[derive(Clone, Copy, RustcDecodable, RustcEncodable, PartialEq)]
+#[derive(Clone, Copy, Eq, RustcDecodable, RustcEncodable, PartialEq)]
 #[cfg_attr(feature = "plugins", derive(HeapSizeOf, Deserialize, Serialize))]
 pub struct Size2D<T> {
     pub width: T,