diff --git a/components/style/properties/longhand/background.mako.rs b/components/style/properties/longhand/background.mako.rs
index ad5562226ce..35420469f56 100644
--- a/components/style/properties/longhand/background.mako.rs
+++ b/components/style/properties/longhand/background.mako.rs
@@ -8,9 +8,11 @@
 
 ${helpers.predefined_type("background-color", "CSSColor",
     "::cssparser::Color::RGBA(::cssparser::RGBA { red: 0., green: 0., blue: 0., alpha: 0. }) /* transparent */",
+    spec="https://drafts.csswg.org/css-backgrounds/#background-color",
     animatable=True, complex_color=True)}
 
 <%helpers:vector_longhand name="background-image" animatable="False"
+                          spec="https://drafts.csswg.org/css-backgrounds/#the-background-image"
                           has_uncacheable_values="${product == 'gecko'}">
     use std::fmt;
     use style_traits::ToCss;
@@ -86,7 +88,8 @@ ${helpers.predefined_type("background-color", "CSSColor",
     }
 </%helpers:vector_longhand>
 
-<%helpers:vector_longhand name="background-position-x" animatable="True">
+<%helpers:vector_longhand name="background-position-x" animatable="True"
+                          spec="https://drafts.csswg.org/css-backgrounds-4/#propdef-background-position-x">
     use std::fmt;
     use style_traits::ToCss;
     use values::HasViewportPercentage;
@@ -135,7 +138,8 @@ ${helpers.predefined_type("background-color", "CSSColor",
     }
 </%helpers:vector_longhand>
 
-<%helpers:vector_longhand name="background-position-y" animatable="True">
+<%helpers:vector_longhand name="background-position-y" animatable="True"
+                          spec="https://drafts.csswg.org/css-backgrounds-4/#propdef-background-position-y">
     use std::fmt;
     use style_traits::ToCss;
     use values::HasViewportPercentage;
@@ -188,24 +192,29 @@ ${helpers.predefined_type("background-color", "CSSColor",
 ${helpers.single_keyword("background-repeat",
                          "repeat repeat-x repeat-y space round no-repeat",
                          vector=True,
+                         spec="https://drafts.csswg.org/css-backgrounds/#the-background-repeat",
                          animatable=False)}
 
 ${helpers.single_keyword("background-attachment",
                          "scroll fixed" + (" local" if product == "gecko" else ""),
                          vector=True,
+                         spec="https://drafts.csswg.org/css-backgrounds/#the-background-attachment",
                          animatable=False)}
 
 ${helpers.single_keyword("background-clip",
                          "border-box padding-box content-box",
                          vector=True,
+                         spec="https://drafts.csswg.org/css-backgrounds/#the-background-clip",
                          animatable=False)}
 
 ${helpers.single_keyword("background-origin",
                          "padding-box border-box content-box",
                          vector=True,
+                         spec="https://drafts.csswg.org/css-backgrounds/#the-background-origin",
                          animatable=False)}
 
-<%helpers:vector_longhand name="background-size" animatable="True">
+<%helpers:vector_longhand name="background-size" animatable="True"
+                          spec="https://drafts.csswg.org/css-backgrounds/#the-background-size">
     use cssparser::Token;
     use std::ascii::AsciiExt;
     use std::fmt;
@@ -406,4 +415,5 @@ ${helpers.single_keyword("background-blend-mode",
                          """normal multiply screen overlay darken lighten color-dodge
                             color-burn hard-light soft-light difference exclusion hue
                             saturation color luminosity""",
-                         vector="true", products="gecko", animatable=False)}
+                         vector="true", products="gecko", animatable=False,
+                         spec="https://drafts.fxtf.org/compositing/#background-blend-mode")}
diff --git a/components/style/properties/shorthand/background.mako.rs b/components/style/properties/shorthand/background.mako.rs
index d6ba7da83b8..857a728a7bb 100644
--- a/components/style/properties/shorthand/background.mako.rs
+++ b/components/style/properties/shorthand/background.mako.rs
@@ -8,7 +8,8 @@
 <%helpers:shorthand name="background"
                     sub_properties="background-color background-position-x background-position-y background-repeat
                                     background-attachment background-image background-size background-origin
-                                    background-clip">
+                                    background-clip"
+                    spec="https://drafts.csswg.org/css-backgrounds/#the-background">
     use properties::longhands::{background_color, background_position_x, background_position_y, background_repeat};
     use properties::longhands::{background_attachment, background_image, background_size, background_origin};
     use properties::longhands::background_clip;
@@ -252,7 +253,8 @@
 </%helpers:shorthand>
 
 <%helpers:shorthand name="background-position"
-                    sub_properties="background-position-x background-position-y">
+                    sub_properties="background-position-x background-position-y"
+                    spec="https://drafts.csswg.org/css-backgrounds-4/#the-background-position">
     use properties::longhands::{background_position_x,background_position_y};
     use values::specified::position::Position;
     use parser::Parse;