--- a/servo/components/style/build_gecko.rs
+++ b/servo/components/style/build_gecko.rs
@@ -26,16 +26,17 @@ mod common {
             BuildType::Release => STRUCTS_RELEASE_FILE
         }
     }
 }
 
 #[cfg(feature = "bindgen")]
 mod bindings {
     use bindgen::{Builder, CodegenConfig};
+    use bindgen::chooser::{EnumVariantCustomBehavior, EnumVariantValue, TypeChooser};
     use regex::Regex;
     use std::cmp;
     use std::collections::HashSet;
     use std::env;
     use std::fs::{self, File};
     use std::io::{Read, Write};
     use std::path::{Path, PathBuf};
     use std::sync::Mutex;
@@ -253,16 +254,33 @@ mod bindings {
         let re = Regex::new(r#"^SERVO_ARC_TYPE\(\w+,\s*(\w+)\)$"#).unwrap();
         content.lines().map(|line| line.trim()).filter(|line| !line.is_empty())
             .map(|line| re.captures(&line)
                  .expect(&format!("Unrecognized line in ServoArcTypeList.h: '{}'", line))
                  .get(1).unwrap().as_str().to_string())
             .collect()
     }
 
+    #[derive(Debug)]
+    struct Callbacks;
+    impl TypeChooser for Callbacks {
+        fn enum_variant_behavior(&self,
+                                 enum_name: Option<&str>,
+                                 variant_name: &str,
+                                 _variant_value: EnumVariantValue)
+                                 -> Option<EnumVariantCustomBehavior> {
+            if enum_name.map_or(false, |n| n == "nsCSSPropertyID") &&
+               variant_name.starts_with("eCSSProperty_COUNT") {
+                Some(EnumVariantCustomBehavior::Constify)
+            } else {
+                None
+            }
+        }
+    }
+
     pub fn generate_structs(build_type: BuildType) {
         let mut builder = Builder::get_initial_builder(build_type)
             .enable_cxx_namespaces()
             .with_codegen_config(CodegenConfig {
                 types: true,
                 vars: true,
                 ..CodegenConfig::nothing()
             })
@@ -291,17 +309,18 @@ mod bindings {
             .raw_line("pub use self::root::mozilla::*;")
             .raw_line("pub use self::root::mozilla::css::*;")
             .raw_line("pub use self::root::mozilla::dom::*;")
             .raw_line("use atomic_refcell::AtomicRefCell;")
             .raw_line("use data::ElementData;")
             .hide_type("nsString")
             .bitfield_enum("nsChangeHint")
             .bitfield_enum("nsRestyleHint")
-            .constified_enum("UpdateAnimationsTasks");
+            .constified_enum("UpdateAnimationsTasks")
+            .type_chooser(Box::new(Callbacks));
         let whitelist_vars = [
             "NS_THEME_.*",
             "NODE_.*",
             "NS_FONT_.*",
             "NS_STYLE_.*",
             "NS_MATHML_.*",
             "NS_RADIUS_.*",
             "BORDER_COLOR_.*",

--- a/servo/components/style/properties/gecko.mako.rs
+++ b/servo/components/style/properties/gecko.mako.rs
@@ -1890,28 +1890,28 @@ fn static_assert() {
         computed_value::T(Some(result))
     }
 
     ${impl_transition_time_value('delay', 'Delay')}
     ${impl_transition_time_value('duration', 'Duration')}
     ${impl_transition_timing_function()}
 
     pub fn set_transition_property(&mut self, v: longhands::transition_property::computed_value::T) {
-        use gecko_bindings::structs::nsCSSPropertyID_eCSSPropertyExtra_no_properties;
+        use gecko_bindings::structs::nsCSSPropertyID::eCSSPropertyExtra_no_properties;
 
         if !v.0.is_empty() {
             unsafe { self.gecko.mTransitions.ensure_len(v.0.len()) };
             self.gecko.mTransitionPropertyCount = v.0.len() as u32;
             for (servo, gecko) in v.0.into_iter().zip(self.gecko.mTransitions.iter_mut()) {
                 gecko.mProperty = servo.into();
             }
         } else {
             // In gecko |none| is represented by eCSSPropertyExtra_no_properties.
             self.gecko.mTransitionPropertyCount = 1;
-            self.gecko.mTransitions[0].mProperty = nsCSSPropertyID_eCSSPropertyExtra_no_properties;
+            self.gecko.mTransitions[0].mProperty = eCSSPropertyExtra_no_properties;
         }
     }
 
     /// Returns whether there are any transitions specified.
     pub fn specifies_transitions(&self) -> bool {
         use gecko_bindings::structs::nsCSSPropertyID::eCSSPropertyExtra_all_properties;
         if self.gecko.mTransitionPropertyCount == 1 &&
             self.gecko.mTransitions[0].mProperty == eCSSPropertyExtra_all_properties &&

--- a/servo/components/style/properties/helpers.mako.rs
+++ b/servo/components/style/properties/helpers.mako.rs
@@ -730,18 +730,16 @@
             </%def>
         </%self:logical_setter_helper>
         }
     % endif
 </%def>
 
 <%def name="alias_to_nscsspropertyid(alias)">
     <%
-        if alias == "word-wrap":
-            return "nsCSSPropertyID_eCSSPropertyAlias_WordWrap"
         return "nsCSSPropertyID::eCSSPropertyAlias_%s" % to_camel_case(alias)
     %>
 </%def>
 
 <%def name="to_nscsspropertyid(ident)">
     <%
         if ident == "float":
             ident = "float_"