diff --git a/components/style/gecko/conversions.rs b/components/style/gecko/conversions.rs
index e44057bab5d..b4171abb2a8 100644
--- a/components/style/gecko/conversions.rs
+++ b/components/style/gecko/conversions.rs
@@ -17,7 +17,7 @@ use gecko_bindings::structs::{nsStyleImage, nsresult, SheetType};
 use gecko_bindings::sugar::ns_style_coord::{CoordDataValue, CoordData, CoordDataMut};
 use std::f32::consts::PI;
 use stylesheets::{Origin, RulesMutateError};
-use values::computed::{Angle, CalcLengthOrPercentage, ComputedUrl, Gradient, Image};
+use values::computed::{Angle, CalcLengthOrPercentage, ComputedImageUrl, Gradient, Image};
 use values::computed::{Integer, LengthOrPercentage, LengthOrPercentageOrAuto, Percentage, TextAlign};
 use values::generics::box_::VerticalAlign;
 use values::generics::grid::{TrackListValue, TrackSize};
@@ -155,12 +155,12 @@ impl nsStyleImage {
             },
             GenericImage::Url(ref url) => {
                 unsafe {
-                    Gecko_SetLayerImageImageValue(self, url.image_value.as_ref().unwrap().get());
+                    Gecko_SetLayerImageImageValue(self, url.image_value.get());
                 }
             },
             GenericImage::Rect(ref image_rect) => {
                 unsafe {
-                    Gecko_SetLayerImageImageValue(self, image_rect.url.image_value.as_ref().unwrap().get());
+                    Gecko_SetLayerImageImageValue(self, image_rect.url.image_value.get());
                     Gecko_InitializeImageCropRect(self);
 
                     // Set CropRect
@@ -419,13 +419,11 @@ impl nsStyleImage {
         }
     }
 
-    unsafe fn get_image_url(self: &nsStyleImage) -> ComputedUrl {
+    unsafe fn get_image_url(self: &nsStyleImage) -> ComputedImageUrl {
         use gecko_bindings::bindings::Gecko_GetURLValue;
         let url_value = Gecko_GetURLValue(self);
-        let mut url = ComputedUrl::from_url_value_data(url_value.as_ref().unwrap())
-                                    .expect("Could not convert to ComputedUrl");
-        url.build_image_value();
-        url
+        ComputedImageUrl::from_url_value_data(url_value.as_ref().unwrap())
+            .expect("Could not convert to ComputedUrl")
     }
 
     unsafe fn get_gradient(self: &nsStyleImage) -> Box<Gradient> {
diff --git a/components/style/gecko/url.rs b/components/style/gecko/url.rs
index ffe0ddea03b..83d4b05b033 100644
--- a/components/style/gecko/url.rs
+++ b/components/style/gecko/url.rs
@@ -4,13 +4,15 @@
 
 //! Common handling for the specified value CSS url() values.
 
+use cssparser::Parser;
+use gecko_bindings::bindings;
 use gecko_bindings::structs::{ServoBundledURI, URLExtraData};
 use gecko_bindings::structs::mozilla::css::URLValueData;
 use gecko_bindings::structs::root::{nsStyleImageRequest, RustString};
 use gecko_bindings::structs::root::mozilla::css::ImageValue;
 use gecko_bindings::sugar::refptr::RefPtr;
 use malloc_size_of::{MallocSizeOf, MallocSizeOfOps};
-use parser::ParserContext;
+use parser::{Parse, ParserContext};
 use servo_arc::{Arc, RawOffsetArc};
 use std::mem;
 use style_traits::ParseError;
@@ -28,11 +30,6 @@ pub struct SpecifiedUrl {
     /// The URL extra data.
     #[css(skip)]
     pub extra_data: RefPtr<URLExtraData>,
-
-    /// Cache ImageValue, if any, so that we can reuse it while rematching a
-    /// a property with this specified url value.
-    #[css(skip)]
-    pub image_value: Option<RefPtr<ImageValue>>,
 }
 trivial_to_computed_value!(SpecifiedUrl);
 
@@ -47,7 +44,6 @@ impl SpecifiedUrl {
         Ok(SpecifiedUrl {
             serialization: Arc::new(url),
             extra_data: context.url_data.clone(),
-            image_value: None,
         })
     }
 
@@ -71,23 +67,9 @@ impl SpecifiedUrl {
                 Arc::new(url.mStrings.mString.as_ref().to_string())
             },
             extra_data: url.mExtraData.to_safe(),
-            image_value: None,
         })
     }
 
-    /// Convert from nsStyleImageRequest to SpecifiedUrl.
-    pub unsafe fn from_image_request(image_request: &nsStyleImageRequest) -> Result<SpecifiedUrl, ()> {
-        if image_request.mImageValue.mRawPtr.is_null() {
-            return Err(());
-        }
-
-        let image_value = image_request.mImageValue.mRawPtr.as_ref().unwrap();
-        let ref url_value_data = image_value._base;
-        let mut result = Self::from_url_value_data(url_value_data)?;
-        result.build_image_value();
-        Ok(result)
-    }
-
     /// Returns true if this URL looks like a fragment.
     /// See https://drafts.csswg.org/css-values/#local-urls
     pub fn is_fragment(&self) -> bool {
@@ -118,41 +100,90 @@ impl SpecifiedUrl {
             mExtraData: self.extra_data.get(),
         }
     }
-
-    /// Build and carry an image value on request.
-    pub fn build_image_value(&mut self) {
-        use gecko_bindings::bindings::Gecko_ImageValue_Create;
-
-        debug_assert_eq!(self.image_value, None);
-        self.image_value = {
-            unsafe {
-                let ptr = Gecko_ImageValue_Create(self.for_ffi());
-                // We do not expect Gecko_ImageValue_Create returns null.
-                debug_assert!(!ptr.is_null());
-                Some(RefPtr::from_addrefed(ptr))
-            }
-        }
-    }
 }
 
 impl MallocSizeOf for SpecifiedUrl {
     fn size_of(&self, _ops: &mut MallocSizeOfOps) -> usize {
-        use gecko_bindings::bindings::Gecko_ImageValue_SizeOfIncludingThis;
-
-        let mut n = 0;
-
         // XXX: measure `serialization` once bug 1397971 lands
 
         // We ignore `extra_data`, because RefPtr is tricky, and there aren't
         // many of them in practise (sharing is common).
 
-        if let Some(ref image_value) = self.image_value {
-            // Although this is a RefPtr, this is the primary reference because
-            // SpecifiedUrl is responsible for creating the image_value. So we
-            // measure unconditionally here.
-            n += unsafe { Gecko_ImageValue_SizeOfIncludingThis(image_value.get()) };
+        0
+    }
+}
+
+/// A specified url() value for image.
+///
+/// This exists so that we can construct `ImageValue` and reuse it.
+#[derive(Clone, Debug, ToCss)]
+pub struct SpecifiedImageUrl {
+    /// The specified url value.
+    pub url: SpecifiedUrl,
+    /// Gecko's ImageValue so that we can reuse it while rematching a
+    /// property with this specified value.
+    #[css(skip)]
+    pub image_value: RefPtr<ImageValue>,
+}
+trivial_to_computed_value!(SpecifiedImageUrl);
+
+impl SpecifiedImageUrl {
+    fn from_specified_url(url: SpecifiedUrl) -> Self {
+        let image_value = unsafe {
+            let ptr = bindings::Gecko_ImageValue_Create(url.for_ffi());
+            // We do not expect Gecko_ImageValue_Create returns null.
+            debug_assert!(!ptr.is_null());
+            RefPtr::from_addrefed(ptr)
+        };
+        SpecifiedImageUrl { url, image_value }
+    }
+
+    /// Parse a URL from a string value. See SpecifiedUrl::parse_from_string.
+    pub fn parse_from_string<'a>(
+        url: String,
+        context: &ParserContext
+    ) -> Result<Self, ParseError<'a>> {
+        SpecifiedUrl::parse_from_string(url, context).map(Self::from_specified_url)
+    }
+
+    /// Convert from URLValueData to SpecifiedUrl.
+    pub unsafe fn from_url_value_data(url: &URLValueData) -> Result<Self, ()> {
+        SpecifiedUrl::from_url_value_data(url).map(Self::from_specified_url)
+    }
+
+    /// Convert from nsStyleImageRequest to SpecifiedUrl.
+    pub unsafe fn from_image_request(image_request: &nsStyleImageRequest) -> Result<Self, ()> {
+        if image_request.mImageValue.mRawPtr.is_null() {
+            return Err(());
         }
 
+        let image_value = image_request.mImageValue.mRawPtr.as_ref().unwrap();
+        let url_value_data = &image_value._base;
+        Self::from_url_value_data(url_value_data)
+    }
+}
+
+impl Parse for SpecifiedImageUrl {
+    fn parse<'i, 't>(context: &ParserContext, input: &mut Parser<'i, 't>) -> Result<Self, ParseError<'i>> {
+        SpecifiedUrl::parse(context, input).map(Self::from_specified_url)
+    }
+}
+
+impl PartialEq for SpecifiedImageUrl {
+    fn eq(&self, other: &Self) -> bool {
+        self.url.eq(&other.url)
+    }
+}
+
+impl Eq for SpecifiedImageUrl {}
+
+impl MallocSizeOf for SpecifiedImageUrl {
+    fn size_of(&self, ops: &mut MallocSizeOfOps) -> usize {
+        let mut n = self.url.size_of(ops);
+        // Although this is a RefPtr, this is the primary reference because
+        // SpecifiedUrl is responsible for creating the image_value. So we
+        // measure unconditionally here.
+        n += unsafe { bindings::Gecko_ImageValue_SizeOfIncludingThis(self.image_value.get()) };
         n
     }
 }
diff --git a/components/style/properties/gecko.mako.rs b/components/style/properties/gecko.mako.rs
index 6ff85be6d1c..35b3f0bc96c 100644
--- a/components/style/properties/gecko.mako.rs
+++ b/components/style/properties/gecko.mako.rs
@@ -4072,8 +4072,7 @@ fn static_assert() {
             }
             longhands::list_style_image::computed_value::T(Either::First(ref url)) => {
                 unsafe {
-                    Gecko_SetListStyleImageImageValue(&mut self.gecko,
-                                                      url.image_value.as_ref().unwrap().get());
+                    Gecko_SetListStyleImageImageValue(&mut self.gecko, url.image_value.get());
                 }
                 // We don't need to record this struct as uncacheable, like when setting
                 // background-image to a url() value, since only properties in reset structs
@@ -4092,7 +4091,7 @@ fn static_assert() {
     }
 
     pub fn clone_list_style_image(&self) -> longhands::list_style_image::computed_value::T {
-        use values::specified::url::SpecifiedUrl;
+        use values::specified::url::SpecifiedImageUrl;
         use values::{Either, None_};
 
         longhands::list_style_image::computed_value::T(
@@ -4101,8 +4100,8 @@ fn static_assert() {
                 false => {
                     unsafe {
                         let ref gecko_image_request = *self.gecko.mListStyleImage.mRawPtr;
-                        Either::First(SpecifiedUrl::from_image_request(gecko_image_request)
-                                      .expect("mListStyleImage could not convert to SpecifiedUrl"))
+                        Either::First(SpecifiedImageUrl::from_image_request(gecko_image_request)
+                                      .expect("mListStyleImage could not convert to SpecifiedImageUrl"))
                     }
                 }
             }
@@ -5290,8 +5289,10 @@ clip-path
         }
         for i in 0..v.images.len() {
             unsafe {
-                Gecko_SetCursorImageValue(&mut self.gecko.mCursorImages[i],
-                                          v.images[i].url.image_value.as_ref().unwrap().get());
+                Gecko_SetCursorImageValue(
+                    &mut self.gecko.mCursorImages[i],
+                    v.images[i].url.image_value.get(),
+                );
             }
 
             // We don't need to record this struct as uncacheable, like when setting
@@ -5326,7 +5327,7 @@ clip-path
     pub fn clone_cursor(&self) -> longhands::cursor::computed_value::T {
         use values::computed::pointing::CursorImage;
         use style_traits::cursor::CursorKind;
-        use values::specified::url::SpecifiedUrl;
+        use values::specified::url::SpecifiedImageUrl;
 
         let keyword = match self.gecko.mCursor as u32 {
             structs::NS_STYLE_CURSOR_AUTO => CursorKind::Auto,
@@ -5371,8 +5372,8 @@ clip-path
         let images = self.gecko.mCursorImages.iter().map(|gecko_cursor_image| {
             let url = unsafe {
                 let gecko_image_request = gecko_cursor_image.mImage.mRawPtr.as_ref().unwrap();
-                SpecifiedUrl::from_image_request(&gecko_image_request)
-                    .expect("mCursorImages.mImage could not convert to SpecifiedUrl")
+                SpecifiedImageUrl::from_image_request(&gecko_image_request)
+                    .expect("mCursorImages.mImage could not convert to SpecifiedImageUrl")
             };
 
             let hotspot =
@@ -5550,8 +5551,10 @@ clip-path
                         }
                         ContentItem::Url(ref url) => {
                             unsafe {
-                                bindings::Gecko_SetContentDataImageValue(&mut self.gecko.mContents[i],
-                                    url.image_value.as_ref().unwrap().get())
+                                bindings::Gecko_SetContentDataImageValue(
+                                    &mut self.gecko.mContents[i],
+                                    url.image_value.get(),
+                                )
                             }
                         }
                     }
@@ -5578,7 +5581,7 @@ clip-path
         use values::computed::counters::{Content, ContentItem};
         use values::{CustomIdent, Either};
         use values::generics::CounterStyleOrNone;
-        use values::specified::url::SpecifiedUrl;
+        use values::specified::url::SpecifiedImageUrl;
         use values::specified::Attr;
 
         if self.gecko.mContents.is_empty() {
@@ -5641,8 +5644,8 @@ clip-path
                             let gecko_image_request =
                                 &**gecko_content.mContent.mImage.as_ref();
                             ContentItem::Url(
-                                SpecifiedUrl::from_image_request(gecko_image_request)
-                                    .expect("mContent could not convert to SpecifiedUrl")
+                                SpecifiedImageUrl::from_image_request(gecko_image_request)
+                                    .expect("mContent could not convert to SpecifiedImageUrl")
                             )
                         }
                     },
diff --git a/components/style/properties/longhand/box.mako.rs b/components/style/properties/longhand/box.mako.rs
index b02590c7e24..d0da5476bfe 100644
--- a/components/style/properties/longhand/box.mako.rs
+++ b/components/style/properties/longhand/box.mako.rs
@@ -611,7 +611,6 @@ ${helpers.single_keyword("-moz-appearance",
 
 ${helpers.predefined_type("-moz-binding", "UrlOrNone", "Either::Second(None_)",
                           products="gecko",
-                          boxed= product == "gecko",
                           animation_value_type="none",
                           gecko_ffi_name="mBinding",
                           spec="Nonstandard (https://developer.mozilla.org/en-US/docs/Web/CSS/-moz-binding)")}
diff --git a/components/style/properties/longhand/inherited_svg.mako.rs b/components/style/properties/longhand/inherited_svg.mako.rs
index 9e341e8b7c8..a3ab5c3754e 100644
--- a/components/style/properties/longhand/inherited_svg.mako.rs
+++ b/components/style/properties/longhand/inherited_svg.mako.rs
@@ -114,19 +114,16 @@ ${helpers.single_keyword("clip-rule", "nonzero evenodd",
 
 ${helpers.predefined_type("marker-start", "UrlOrNone", "Either::Second(None_)",
                           products="gecko",
-                          boxed= product == "gecko",
                           animation_value_type="discrete",
                           spec="https://www.w3.org/TR/SVG2/painting.html#VertexMarkerProperties")}
 
 ${helpers.predefined_type("marker-mid", "UrlOrNone", "Either::Second(None_)",
                           products="gecko",
-                          boxed= product == "gecko",
                           animation_value_type="discrete",
                           spec="https://www.w3.org/TR/SVG2/painting.html#VertexMarkerProperties")}
 
 ${helpers.predefined_type("marker-end", "UrlOrNone", "Either::Second(None_)",
                           products="gecko",
-                          boxed= product == "gecko",
                           animation_value_type="discrete",
                           spec="https://www.w3.org/TR/SVG2/painting.html#VertexMarkerProperties")}
 
diff --git a/components/style/properties/longhand/list.mako.rs b/components/style/properties/longhand/list.mako.rs
index 3b330c9066f..12a73d0466e 100644
--- a/components/style/properties/longhand/list.mako.rs
+++ b/components/style/properties/longhand/list.mako.rs
@@ -47,7 +47,6 @@ ${helpers.predefined_type("list-style-image",
                           initial_value="specified::ListStyleImage::none()",
                           initial_specified_value="specified::ListStyleImage::none()",
                           animation_value_type="discrete",
-                          boxed=product == "gecko",
                           spec="https://drafts.csswg.org/css-lists/#propdef-list-style-image",
                           servo_restyle_damage="rebuild_and_reflow")}
 
diff --git a/components/style/servo/url.rs b/components/style/servo/url.rs
index 25a4aa5297d..7cfca564dbf 100644
--- a/components/style/servo/url.rs
+++ b/components/style/servo/url.rs
@@ -163,3 +163,5 @@ impl ToComputedValue for SpecifiedUrl {
     }
 }
 
+/// A specified image url() value for servo.
+pub type SpecifiedImageUrl = SpecifiedUrl;
diff --git a/components/style/values/computed/counters.rs b/components/style/values/computed/counters.rs
index 0e3510b8265..1d7659c9d47 100644
--- a/components/style/values/computed/counters.rs
+++ b/components/style/values/computed/counters.rs
@@ -18,7 +18,7 @@ use values::generics::counters::CounterReset as GenericCounterReset;
 #[cfg(feature = "gecko")]
 use values::specified::Attr;
 #[cfg(feature = "gecko")]
-use values::specified::url::SpecifiedUrl;
+use values::specified::url::SpecifiedImageUrl;
 pub use values::specified::{Content, ContentItem};
 
 /// A computed value for the `counter-increment` property.
@@ -79,8 +79,7 @@ impl Parse for Content {
         let mut content = vec![];
         loop {
             #[cfg(feature = "gecko")] {
-                if let Ok(mut url) = input.try(|i| SpecifiedUrl::parse(_context, i)) {
-                    url.build_image_value();
+                if let Ok(url) = input.try(|i| SpecifiedImageUrl::parse(_context, i)) {
                     content.push(ContentItem::Url(url));
                     continue;
                 }
diff --git a/components/style/values/computed/image.rs b/components/style/values/computed/image.rs
index 93fa627a41d..e0b3e3bbd91 100644
--- a/components/style/values/computed/image.rs
+++ b/components/style/values/computed/image.rs
@@ -12,7 +12,8 @@ use std::f32::consts::PI;
 use std::fmt::{self, Write};
 use style_traits::{CssWriter, ToCss};
 use values::{Either, None_};
-use values::computed::{Angle, ComputedUrl, Context, Length, LengthOrPercentage, NumberOrPercentage, ToComputedValue};
+use values::computed::{Angle, ComputedImageUrl, Context};
+use values::computed::{Length, LengthOrPercentage, NumberOrPercentage, ToComputedValue};
 #[cfg(feature = "gecko")]
 use values::computed::Percentage;
 use values::computed::position::Position;
@@ -28,7 +29,7 @@ pub type ImageLayer = Either<None_, Image>;
 
 /// Computed values for an image according to CSS-IMAGES.
 /// <https://drafts.csswg.org/css-images/#image-values>
-pub type Image = GenericImage<Gradient, MozImageRect, ComputedUrl>;
+pub type Image = GenericImage<Gradient, MozImageRect, ComputedImageUrl>;
 
 /// Computed values for a CSS gradient.
 /// <https://drafts.csswg.org/css-images/#gradients>
@@ -76,7 +77,7 @@ pub type GradientItem = GenericGradientItem<RGBA, LengthOrPercentage>;
 pub type ColorStop = GenericColorStop<RGBA, LengthOrPercentage>;
 
 /// Computed values for `-moz-image-rect(...)`.
-pub type MozImageRect = GenericMozImageRect<NumberOrPercentage, ComputedUrl>;
+pub type MozImageRect = GenericMozImageRect<NumberOrPercentage, ComputedImageUrl>;
 
 impl GenericLineDirection for LineDirection {
     fn points_downwards(&self, compat_mode: CompatMode) -> bool {
diff --git a/components/style/values/computed/mod.rs b/components/style/values/computed/mod.rs
index 64e9e389dde..be9985d8cb4 100644
--- a/components/style/values/computed/mod.rs
+++ b/components/style/values/computed/mod.rs
@@ -646,9 +646,17 @@ pub enum ComputedUrl {
     Valid(ServoUrl),
 }
 
-/// TODO: Properly build ComputedUrl for gecko
+/// The computed value of a CSS `url()` for image.
+#[cfg(feature = "servo")]
+pub type ComputedImageUrl = ComputedUrl;
+
+// TODO: Properly build ComputedUrl for gecko
+/// The computed value of a CSS `url()`.
 #[cfg(feature = "gecko")]
 pub type ComputedUrl = specified::url::SpecifiedUrl;
+/// The computed value of a CSS `url()` for image.
+#[cfg(feature = "gecko")]
+pub type ComputedImageUrl = specified::url::SpecifiedImageUrl;
 
 #[cfg(feature = "servo")]
 impl ComputedUrl {
@@ -680,3 +688,6 @@ impl ToCss for ComputedUrl {
 
 /// <url> | <none>
 pub type UrlOrNone = Either<ComputedUrl, None_>;
+
+/// <url> | <none> for image
+pub type ImageUrlOrNone = Either<ComputedImageUrl, None_>;
diff --git a/components/style/values/computed/pointing.rs b/components/style/values/computed/pointing.rs
index 1c44be7681c..9c79462abd6 100644
--- a/components/style/values/computed/pointing.rs
+++ b/components/style/values/computed/pointing.rs
@@ -18,7 +18,7 @@ use style_traits::cursor::CursorKind;
 use values::computed::color::Color;
 use values::generics::pointing::CaretColor as GenericCaretColor;
 #[cfg(feature = "gecko")]
-use values::specified::url::SpecifiedUrl;
+use values::specified::url::SpecifiedImageUrl;
 
 /// The computed value for the `cursor` property.
 ///
@@ -65,10 +65,7 @@ impl Parse for Cursor {
         let mut images = vec![];
         loop {
             match input.try(|input| CursorImage::parse_image(context, input)) {
-                Ok(mut image) => {
-                    image.url.build_image_value();
-                    images.push(image)
-                }
+                Ok(image) => images.push(image),
                 Err(_) => break,
             }
             input.expect_comma()?;
@@ -114,7 +111,7 @@ impl CursorImage {
         input: &mut Parser<'i, 't>
     ) -> Result<Self, ParseError<'i>> {
         Ok(Self {
-            url: SpecifiedUrl::parse(context, input)?,
+            url: SpecifiedImageUrl::parse(context, input)?,
             // FIXME(emilio): Should use Number::parse to handle calc() correctly.
             hotspot: match input.try(|input| input.expect_number()) {
                 Ok(number) => Some((number, input.expect_number()?)),
diff --git a/components/style/values/specified/counters.rs b/components/style/values/specified/counters.rs
index 3252001f142..f7130a79b2f 100644
--- a/components/style/values/specified/counters.rs
+++ b/components/style/values/specified/counters.rs
@@ -18,7 +18,7 @@ use values::generics::counters::CounterReset as GenericCounterReset;
 use values::specified::Attr;
 use values::specified::Integer;
 #[cfg(feature = "gecko")]
-use values::specified::url::SpecifiedUrl;
+use values::specified::url::SpecifiedImageUrl;
 
 /// A specified value for the `counter-increment` property.
 pub type CounterIncrement = GenericCounterIncrement<Integer>;
@@ -119,5 +119,5 @@ pub enum ContentItem {
     Attr(Attr),
     /// `url(url)`
     #[cfg(feature = "gecko")]
-    Url(SpecifiedUrl),
+    Url(SpecifiedImageUrl),
 }
diff --git a/components/style/values/specified/image.rs b/components/style/values/specified/image.rs
index 001e8c09976..331b10be453 100644
--- a/components/style/values/specified/image.rs
+++ b/components/style/values/specified/image.rs
@@ -31,14 +31,14 @@ use values::generics::position::Position as GenericPosition;
 use values::specified::{Angle, Color, Length, LengthOrPercentage};
 use values::specified::{Number, NumberOrPercentage, Percentage, RGBAColor};
 use values::specified::position::{LegacyPosition, Position, PositionComponent, Side, X, Y};
-use values::specified::url::SpecifiedUrl;
+use values::specified::url::SpecifiedImageUrl;
 
 /// A specified image layer.
 pub type ImageLayer = Either<None_, Image>;
 
 /// Specified values for an image according to CSS-IMAGES.
 /// <https://drafts.csswg.org/css-images/#image-values>
-pub type Image = GenericImage<Gradient, MozImageRect, SpecifiedUrl>;
+pub type Image = GenericImage<Gradient, MozImageRect, SpecifiedImageUrl>;
 
 /// Specified values for a CSS gradient.
 /// <https://drafts.csswg.org/css-images/#gradients>
@@ -124,16 +124,11 @@ pub type ColorStop = GenericColorStop<RGBAColor, LengthOrPercentage>;
 
 /// Specified values for `moz-image-rect`
 /// -moz-image-rect(<uri>, top, right, bottom, left);
-pub type MozImageRect = GenericMozImageRect<NumberOrPercentage, SpecifiedUrl>;
+pub type MozImageRect = GenericMozImageRect<NumberOrPercentage, SpecifiedImageUrl>;
 
 impl Parse for Image {
-    #[cfg_attr(not(feature = "gecko"), allow(unused_mut))]
     fn parse<'i, 't>(context: &ParserContext, input: &mut Parser<'i, 't>) -> Result<Image, ParseError<'i>> {
-        if let Ok(mut url) = input.try(|input| SpecifiedUrl::parse(context, input)) {
-            #[cfg(feature = "gecko")]
-            {
-                url.build_image_value();
-            }
+        if let Ok(url) = input.try(|input| SpecifiedImageUrl::parse(context, input)) {
             return Ok(GenericImage::Url(url));
         }
         if let Ok(gradient) = input.try(|i| Gradient::parse(context, i)) {
@@ -145,11 +140,7 @@ impl Parse for Image {
                 return Ok(GenericImage::PaintWorklet(paint_worklet));
             }
         }
-        if let Ok(mut image_rect) = input.try(|input| MozImageRect::parse(context, input)) {
-            #[cfg(feature = "gecko")]
-            {
-                image_rect.url.build_image_value();
-            }
+        if let Ok(image_rect) = input.try(|input| MozImageRect::parse(context, input)) {
             return Ok(GenericImage::Rect(Box::new(image_rect)));
         }
         Ok(GenericImage::Element(Image::parse_element(input)?))
@@ -944,7 +935,7 @@ impl Parse for MozImageRect {
         input.try(|i| i.expect_function_matching("-moz-image-rect"))?;
         input.parse_nested_block(|i| {
             let string = i.expect_url_or_string()?;
-            let url = SpecifiedUrl::parse_from_string(string.as_ref().to_owned(), context)?;
+            let url = SpecifiedImageUrl::parse_from_string(string.as_ref().to_owned(), context)?;
             i.expect_comma()?;
             let top = NumberOrPercentage::parse_non_negative(context, i)?;
             i.expect_comma()?;
@@ -953,14 +944,7 @@ impl Parse for MozImageRect {
             let bottom = NumberOrPercentage::parse_non_negative(context, i)?;
             i.expect_comma()?;
             let left = NumberOrPercentage::parse_non_negative(context, i)?;
-
-            Ok(MozImageRect {
-                url: url,
-                top: top,
-                right: right,
-                bottom: bottom,
-                left: left,
-            })
+            Ok(MozImageRect { url, top, right, bottom, left })
         })
     }
 }
diff --git a/components/style/values/specified/list.rs b/components/style/values/specified/list.rs
index 9acba5ca1e5..f2bc6068790 100644
--- a/components/style/values/specified/list.rs
+++ b/components/style/values/specified/list.rs
@@ -13,7 +13,7 @@ use values::{Either, None_};
 use values::CustomIdent;
 #[cfg(feature = "gecko")]
 use values::generics::CounterStyleOrNone;
-use values::specified::UrlOrNone;
+use values::specified::ImageUrlOrNone;
 
 /// Specified and computed `list-style-type` property.
 #[cfg(feature = "gecko")]
@@ -75,7 +75,7 @@ impl Parse for ListStyleType {
 
 /// Specified and computed `list-style-image` property.
 #[derive(Clone, Debug, MallocSizeOf, PartialEq, ToCss)]
-pub struct ListStyleImage(pub UrlOrNone);
+pub struct ListStyleImage(pub ImageUrlOrNone);
 
 // FIXME(nox): This is wrong, there are different types for specified
 // and computed URLs in Servo.
@@ -90,19 +90,11 @@ impl ListStyleImage {
 }
 
 impl Parse for ListStyleImage {
-    fn parse<'i, 't>(context: &ParserContext, input: &mut Parser<'i, 't>)
-                         -> Result<ListStyleImage, ParseError<'i>> {
-        #[allow(unused_mut)]
-        let mut value = input.try(|input| UrlOrNone::parse(context, input))?;
-
-        #[cfg(feature = "gecko")]
-        {
-            if let Either::First(ref mut url) = value {
-                url.build_image_value();
-            }
-        }
-
-        return Ok(ListStyleImage(value));
+    fn parse<'i, 't>(
+        context: &ParserContext,
+        input: &mut Parser<'i, 't>,
+    ) -> Result<ListStyleImage, ParseError<'i>> {
+        ImageUrlOrNone::parse(context, input).map(ListStyleImage)
     }
 }
 
diff --git a/components/style/values/specified/mod.rs b/components/style/values/specified/mod.rs
index 017d1dfccb1..56126fa7d34 100644
--- a/components/style/values/specified/mod.rs
+++ b/components/style/values/specified/mod.rs
@@ -11,7 +11,7 @@ use context::QuirksMode;
 use cssparser::{Parser, Token, serialize_identifier};
 use num_traits::One;
 use parser::{ParserContext, Parse};
-use self::url::SpecifiedUrl;
+use self::url::{SpecifiedImageUrl, SpecifiedUrl};
 use std::f32;
 use std::fmt::{self, Write};
 use style_traits::{CssWriter, ParseError, StyleParseErrorKind, ToCss};
@@ -534,6 +534,9 @@ impl Parse for PositiveInteger {
 #[allow(missing_docs)]
 pub type UrlOrNone = Either<SpecifiedUrl, None_>;
 
+/// The specified value of a `<url>` for image or `none`.
+pub type ImageUrlOrNone = Either<SpecifiedImageUrl, None_>;
+
 /// The specified value of a grid `<track-breadth>`
 pub type TrackBreadth = GenericTrackBreadth<LengthOrPercentage>;
 
diff --git a/components/style/values/specified/pointing.rs b/components/style/values/specified/pointing.rs
index 0628746f261..d8da1305efb 100644
--- a/components/style/values/specified/pointing.rs
+++ b/components/style/values/specified/pointing.rs
@@ -13,7 +13,7 @@ use style_traits::cursor::CursorKind;
 use values::generics::pointing::CaretColor as GenericCaretColor;
 use values::specified::color::Color;
 #[cfg(feature = "gecko")]
-use values::specified::url::SpecifiedUrl;
+use values::specified::url::SpecifiedImageUrl;
 
 /// The specified value for the `cursor` property.
 ///
@@ -39,7 +39,7 @@ pub struct Cursor {
 #[derive(Clone, Debug, MallocSizeOf, PartialEq, ToComputedValue)]
 pub struct CursorImage {
     /// The url to parse images from.
-    pub url: SpecifiedUrl,
+    pub url: SpecifiedImageUrl,
     /// The <x> and <y> coordinates.
     pub hotspot: Option<(f32, f32)>,
 }
diff --git a/ports/geckolib/glue.rs b/ports/geckolib/glue.rs
index 40f5bae66eb..8e0ee71738b 100644
--- a/ports/geckolib/glue.rs
+++ b/ports/geckolib/glue.rs
@@ -3544,7 +3544,7 @@ pub extern "C" fn Servo_DeclarationBlock_SetBackgroundImage(
     use style::properties::longhands::background_image::SpecifiedValue as BackgroundImage;
     use style::values::Either;
     use style::values::generics::image::Image;
-    use style::values::specified::url::SpecifiedUrl;
+    use style::values::specified::url::SpecifiedImageUrl;
 
     let url_data = unsafe { RefPtr::from_ptr_ref(&raw_extra_data) };
     let string = unsafe { (*value).to_string() };
@@ -3555,8 +3555,7 @@ pub extern "C" fn Servo_DeclarationBlock_SetBackgroundImage(
         ParsingMode::DEFAULT,
         QuirksMode::NoQuirks,
     );
-    if let Ok(mut url) = SpecifiedUrl::parse_from_string(string.into(), &context) {
-        url.build_image_value();
+    if let Ok(url) = SpecifiedImageUrl::parse_from_string(string.into(), &context) {
         let decl = PropertyDeclaration::BackgroundImage(BackgroundImage(
             vec![Either::Second(Image::Url(url))]
         ));
diff --git a/ports/geckolib/tests/size_of.rs b/ports/geckolib/tests/size_of.rs
index 0f24603fb4e..9691c4cd385 100644
--- a/ports/geckolib/tests/size_of.rs
+++ b/ports/geckolib/tests/size_of.rs
@@ -42,10 +42,10 @@ size_of_test!(test_size_of_rule_node, RuleNode, 80);
 // we only pass `&mut SourcePropertyDeclaration` references around.
 size_of_test!(test_size_of_parsed_declaration, style::properties::SourcePropertyDeclaration, 608);
 
-size_of_test!(test_size_of_computed_image, computed::image::Image, 40);
-size_of_test!(test_size_of_specified_image, specified::image::Image, 40);
+size_of_test!(test_size_of_computed_image, computed::image::Image, 32);
+size_of_test!(test_size_of_specified_image, specified::image::Image, 32);
 
 // FIXME(bz): These can shrink if we move the None_ value inside the
 // enum instead of paying an extra word for the Either discriminant.
-size_of_test!(test_size_of_computed_image_layer, computed::image::ImageLayer, 40);
-size_of_test!(test_size_of_specified_image_layer, specified::image::ImageLayer, 40);
+size_of_test!(test_size_of_computed_image_layer, computed::image::ImageLayer, 32);
+size_of_test!(test_size_of_specified_image_layer, specified::image::ImageLayer, 32);