diff --git a/components/style/gecko/media_queries.rs b/components/style/gecko/media_queries.rs
index 833db60a037..9dbfb5c8cb9 100644
--- a/components/style/gecko/media_queries.rs
+++ b/components/style/gecko/media_queries.rs
@@ -229,7 +229,7 @@ impl Device {
 }
 
 /// The kind of matching that should be performed on a media feature value.
-#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq)]
 pub enum Range {
     /// At least the specified value.
     Min,
@@ -241,7 +241,7 @@ pub enum Range {
 
 /// A expression for gecko contains a reference to the media feature, the value
 /// the media query contained, and the range to evaluate.
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, MallocSizeOf)]
 pub struct Expression {
     feature: &'static nsMediaFeature,
     value: Option<MediaExpressionValue>,
@@ -294,7 +294,7 @@ impl PartialEq for Expression {
 /// If the first, this would need to store the relevant values.
 ///
 /// See: https://github.com/w3c/csswg-drafts/issues/1968
-#[derive(Clone, Debug, PartialEq)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq)]
 pub enum MediaExpressionValue {
     /// A length.
     Length(Length),
diff --git a/components/style/media_queries.rs b/components/style/media_queries.rs
index 5742e794c3f..11cf6c85dc7 100644
--- a/components/style/media_queries.rs
+++ b/components/style/media_queries.rs
@@ -24,9 +24,8 @@ pub use servo::media_queries::{Device, Expression};
 pub use gecko::media_queries::{Device, Expression};
 
 /// A type that encapsulates a media query list.
-#[cfg_attr(feature = "servo", derive(MallocSizeOf))]
 #[css(comma)]
-#[derive(Clone, Debug, ToCss)]
+#[derive(Clone, Debug, MallocSizeOf, ToCss)]
 pub struct MediaList {
     /// The list of media queries.
     #[css(iterable)]
@@ -43,8 +42,7 @@ impl MediaList {
 }
 
 /// <https://drafts.csswg.org/mediaqueries/#mq-prefix>
-#[cfg_attr(feature = "servo", derive(MallocSizeOf))]
-#[derive(Clone, Copy, Debug, Eq, PartialEq, ToCss)]
+#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, ToCss)]
 pub enum Qualifier {
     /// Hide a media query from legacy UAs:
     /// <https://drafts.csswg.org/mediaqueries/#mq-only>
@@ -57,8 +55,7 @@ pub enum Qualifier {
 /// A [media query][mq].
 ///
 /// [mq]: https://drafts.csswg.org/mediaqueries/
-#[derive(Clone, Debug, PartialEq)]
-#[cfg_attr(feature = "servo", derive(MallocSizeOf))]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq)]
 pub struct MediaQuery {
     /// The qualifier for this query.
     pub qualifier: Option<Qualifier>,
@@ -123,8 +120,7 @@ impl ToCss for MediaQuery {
 }
 
 /// <http://dev.w3.org/csswg/mediaqueries-3/#media0>
-#[derive(Clone, Debug, Eq, PartialEq)]
-#[cfg_attr(feature = "servo", derive(MallocSizeOf))]
+#[derive(Clone, Debug, Eq, MallocSizeOf, PartialEq)]
 pub enum MediaQueryType {
     /// A media type that matches every device.
     All,
@@ -152,8 +148,7 @@ impl MediaQueryType {
 }
 
 /// <https://drafts.csswg.org/mediaqueries/#media-types>
-#[derive(Clone, Debug, Eq, PartialEq)]
-#[cfg_attr(feature = "servo", derive(MallocSizeOf))]
+#[derive(Clone, Debug, Eq, MallocSizeOf, PartialEq)]
 pub struct MediaType(pub CustomIdent);
 
 impl MediaType {
@@ -180,6 +175,7 @@ impl MediaType {
         }
     }
 }
+
 impl MediaQuery {
     /// Parse a media query given css input.
     ///
diff --git a/components/style/values/specified/resolution.rs b/components/style/values/specified/resolution.rs
index 52da8eaea34..2965b65821a 100644
--- a/components/style/values/specified/resolution.rs
+++ b/components/style/values/specified/resolution.rs
@@ -12,7 +12,7 @@ use style_traits::{ParseError, StyleParseErrorKind};
 use values::CSSFloat;
 
 /// A specified resolution.
-#[derive(Clone, Debug, PartialEq, ToCss)]
+#[derive(Clone, Debug, PartialEq, MallocSizeOf, ToCss)]
 pub enum Resolution {
     /// Dots per inch.
     #[css(dimension)]