diff --git a/components/style/cbindgen.toml b/components/style/cbindgen.toml
index 6005126fb27..27ad7bc80a1 100644
--- a/components/style/cbindgen.toml
+++ b/components/style/cbindgen.toml
@@ -50,6 +50,7 @@ include = [
   "ComputedTimingFunction",
   "Display",
   "DisplayMode",
+  "ExtremumLength",
   "FillRule",
   "FontDisplay",
   "FontFaceSourceListComponent",
diff --git a/components/style/gecko/values.rs b/components/style/gecko/values.rs
index 59ccd0afeca..8006d50925f 100644
--- a/components/style/gecko/values.rs
+++ b/components/style/gecko/values.rs
@@ -362,40 +362,13 @@ impl GeckoStyleCoordConvertible for Normal {
 
 impl GeckoStyleCoordConvertible for ExtremumLength {
     fn to_gecko_style_coord<T: CoordDataMut>(&self, coord: &mut T) {
-        use crate::gecko_bindings::structs::{
-            NS_STYLE_WIDTH_AVAILABLE, NS_STYLE_WIDTH_FIT_CONTENT,
-        };
-        use crate::gecko_bindings::structs::{
-            NS_STYLE_WIDTH_MAX_CONTENT, NS_STYLE_WIDTH_MIN_CONTENT,
-        };
-        coord.set_value(CoordDataValue::Enumerated(match *self {
-            ExtremumLength::MozMaxContent => NS_STYLE_WIDTH_MAX_CONTENT,
-            ExtremumLength::MozMinContent => NS_STYLE_WIDTH_MIN_CONTENT,
-            ExtremumLength::MozFitContent => NS_STYLE_WIDTH_FIT_CONTENT,
-            ExtremumLength::MozAvailable => NS_STYLE_WIDTH_AVAILABLE,
-        }))
+        coord.set_value(CoordDataValue::Enumerated(*self as u32));
     }
 
     fn from_gecko_style_coord<T: CoordData>(coord: &T) -> Option<Self> {
-        use crate::gecko_bindings::structs::{
-            NS_STYLE_WIDTH_AVAILABLE, NS_STYLE_WIDTH_FIT_CONTENT,
-        };
-        use crate::gecko_bindings::structs::{
-            NS_STYLE_WIDTH_MAX_CONTENT, NS_STYLE_WIDTH_MIN_CONTENT,
-        };
+        use num_traits::FromPrimitive;
         match coord.as_value() {
-            CoordDataValue::Enumerated(NS_STYLE_WIDTH_MAX_CONTENT) => {
-                Some(ExtremumLength::MozMaxContent)
-            },
-            CoordDataValue::Enumerated(NS_STYLE_WIDTH_MIN_CONTENT) => {
-                Some(ExtremumLength::MozMinContent)
-            },
-            CoordDataValue::Enumerated(NS_STYLE_WIDTH_FIT_CONTENT) => {
-                Some(ExtremumLength::MozFitContent)
-            },
-            CoordDataValue::Enumerated(NS_STYLE_WIDTH_AVAILABLE) => {
-                Some(ExtremumLength::MozAvailable)
-            },
+            CoordDataValue::Enumerated(v) => ExtremumLength::from_u32(v),
             _ => None,
         }
     }
diff --git a/components/style/values/computed/length.rs b/components/style/values/computed/length.rs
index 96886e9096a..7592c3a2cae 100644
--- a/components/style/values/computed/length.rs
+++ b/components/style/values/computed/length.rs
@@ -975,6 +975,7 @@ pub type NonNegativeLengthOrPercentageOrNormal = Either<NonNegativeLengthOrPerce
     Copy,
     Debug,
     Eq,
+    FromPrimitive,
     MallocSizeOf,
     Parse,
     PartialEq,
@@ -982,6 +983,7 @@ pub type NonNegativeLengthOrPercentageOrNormal = Either<NonNegativeLengthOrPerce
     ToComputedValue,
     ToCss,
 )]
+#[repr(u8)]
 pub enum ExtremumLength {
     MozMaxContent,
     MozMinContent,