diff --git a/components/style/properties/data.py b/components/style/properties/data.py
index 2b11109bbc4..274da76571c 100644
--- a/components/style/properties/data.py
+++ b/components/style/properties/data.py
@@ -63,7 +63,7 @@ class Longhand(object):
     def __init__(self, style_struct, name, animatable=None, derived_from=None, keyword=None,
                  predefined_type=None, custom_cascade=False, experimental=False, internal=False,
                  need_clone=False, need_index=False, gecko_ffi_name=None, depend_on_viewport_size=False,
-                 allowed_in_keyframe_block=True, complex_color=False):
+                 allowed_in_keyframe_block=True, complex_color=False, cast_type='u8'):
         self.name = name
         self.keyword = keyword
         self.predefined_type = predefined_type
@@ -78,6 +78,7 @@ class Longhand(object):
         self.depend_on_viewport_size = depend_on_viewport_size
         self.derived_from = (derived_from or "").split()
         self.complex_color = complex_color
+        self.cast_type = cast_type
 
         # https://drafts.csswg.org/css-animations/#keyframes
         # > The <declaration-list> inside of <keyframe-block> accepts any CSS property
diff --git a/components/style/properties/gecko.mako.rs b/components/style/properties/gecko.mako.rs
index 85ebdfdaaab..46bcd37d534 100644
--- a/components/style/properties/gecko.mako.rs
+++ b/components/style/properties/gecko.mako.rs
@@ -490,21 +490,29 @@ impl Debug for ${style_struct.gecko_struct_name} {
         "CSSColor": impl_color,
     }
 
-    def predefined_type_method(longhand):
+    def longhand_method(longhand):
         args = dict(ident=longhand.ident, gecko_ffi_name=longhand.gecko_ffi_name,
                     need_clone=longhand.need_clone)
-        method = predefined_types[longhand.predefined_type]
 
-        # additional type-specific arguments
-        if longhand.predefined_type in ["CSSColor"]:
-            args.update(complex_color=longhand.complex_color)
+        # get the method and pass additional keyword or type-specific arguments
+        if longhand.keyword:
+            method = impl_keyword
+            args.update(keyword=longhand.keyword)
+            if "font" in longhand.ident:
+                args.update(cast_type=longhand.cast_type)
+        else:
+            method = predefined_types[longhand.predefined_type]
+            if longhand.predefined_type in ["CSSColor"]:
+                args.update(complex_color=longhand.complex_color)
 
         method(**args)
 
-    keyword_longhands = [x for x in longhands if x.keyword and x.name not in force_stub]
-    predefined_longhands = [x for x in longhands
-                            if x.predefined_type in predefined_types and x.name not in force_stub]
-    stub_longhands = [x for x in longhands if x not in keyword_longhands + predefined_longhands]
+    picked_longhands, stub_longhands = [], []
+    for x in longhands:
+        if (x.keyword or x.predefined_type in predefined_types) and x.name not in force_stub:
+            picked_longhands.append(x)
+        else:
+            stub_longhands.append(x)
 
     # If one of the longhands is not handled
     # by either:
@@ -518,6 +526,7 @@ impl Debug for ${style_struct.gecko_struct_name} {
     # If you hit this error, please add `product="servo"` to the longhand.
     # In case the longhand is used in a shorthand, add it to the force_stub
     # list above.
+
     for stub in stub_longhands:
        if stub.name not in force_stub:
            raise Exception("Don't know what to do with longhand %s in style struct %s"
@@ -533,10 +542,8 @@ impl ${style_struct.gecko_struct_name} {
      * Auto-Generated Methods.
      */
     <%
-    for longhand in keyword_longhands:
-        impl_keyword(longhand.ident, longhand.gecko_ffi_name, longhand.keyword, longhand.need_clone)
-    for longhand in predefined_longhands:
-        predefined_type_method(longhand)
+    for longhand in picked_longhands:
+        longhand_method(longhand)
     %>
 
     /*