diff --git a/src/components/script/dom/htmliframeelement.rs b/src/components/script/dom/htmliframeelement.rs
index aecd41f9119f..d0bad030a866 100644
--- a/src/components/script/dom/htmliframeelement.rs
+++ b/src/components/script/dom/htmliframeelement.rs
@@ -116,6 +116,7 @@ impl HTMLIFrameElement {
         if "sandbox" == name {
             let mut modes = AllowNothing as u8;
             for word in value.split_iter(' ') {
+                // FIXME: Workaround for https://github.com/mozilla/rust/issues/10683
                 let word_lower = word.to_ascii_lower();
                 modes |= match word_lower.as_slice() {
                     "allow-same-origin" => AllowSameOrigin,
diff --git a/src/components/style/common_types.rs b/src/components/style/common_types.rs
index fbd4afeb85e3..4eace37554eb 100644
--- a/src/components/style/common_types.rs
+++ b/src/components/style/common_types.rs
@@ -50,6 +50,7 @@ pub mod specified {
             Length::parse_internal(input, /* negative_ok = */ false)
         }
         pub fn parse_dimension(value: CSSFloat, unit: &str) -> Option<Length> {
+            // FIXME: Workaround for https://github.com/mozilla/rust/issues/10683
             let unit_lower = unit.to_ascii_lower(); 
             match unit_lower.as_slice() {
                 "px" => Some(Length::from_px(value)),
diff --git a/src/components/style/media_queries.rs b/src/components/style/media_queries.rs
index 00571fdd00e1..abccc41e7f51 100644
--- a/src/components/style/media_queries.rs
+++ b/src/components/style/media_queries.rs
@@ -82,6 +82,7 @@ pub fn parse_media_query_list(input: &[ComponentValue]) -> MediaQueryList {
     loop {
         let mq = match next {
             Some(&Ident(ref value)) => {
+                // FIXME: Workaround for https://github.com/mozilla/rust/issues/10683
                 let value_lower = value.to_ascii_lower(); 
                 match value_lower.as_slice() {
                     "screen" => Some(MediaQuery{ media_type: MediaType(Screen) }),
diff --git a/src/components/style/properties.rs.mako b/src/components/style/properties.rs.mako
index d7b24c8edb86..5fefde01f4b5 100644
--- a/src/components/style/properties.rs.mako
+++ b/src/components/style/properties.rs.mako
@@ -190,6 +190,7 @@ pub mod longhands {
     pub fn parse_border_width(component_value: &ComponentValue) -> Option<specified::Length> {
         match component_value {
             &Ident(ref value) => {
+                // FIXME: Workaround for https://github.com/mozilla/rust/issues/10683
                 let value_lower = value.to_ascii_lower(); 
                 match value_lower.as_slice() {
                     "thin" => Some(specified::Length::from_px(1.)),
@@ -336,6 +337,7 @@ pub mod longhands {
         pub fn from_component_value(input: &ComponentValue) -> Option<SpecifiedValue> {
             match input {
                 &Ident(ref value) => {
+                    // FIXME: Workaround for https://github.com/mozilla/rust/issues/10683
                     let value_lower = value.to_ascii_lower(); 
                     match value_lower.as_slice() {
                         % for keyword in vertical_align_keywords:
@@ -460,6 +462,7 @@ pub mod longhands {
                     // TODO: avoid copying strings?
                     Some(&String(ref value)) => add!(FamilyName(value.to_owned())),
                     Some(&Ident(ref value)) => {
+                        // FIXME: Workaround for https://github.com/mozilla/rust/issues/10683
                         let value = value.as_slice();
                         let value_lower = value.to_ascii_lower(); 
                         match value_lower.as_slice() {
@@ -511,6 +514,7 @@ pub mod longhands {
         pub fn from_component_value(input: &ComponentValue) -> Option<SpecifiedValue> {
             match input {
                 &Ident(ref value) => {
+                    // FIXME: Workaround for https://github.com/mozilla/rust/issues/10683
                     let value_lower = value.to_ascii_lower();  
                     match value_lower.as_slice() {
                         "bold" => Some(SpecifiedWeight700),
diff --git a/src/components/style/selectors.rs b/src/components/style/selectors.rs
index 1a99eb3f8563..3935121fadc4 100644
--- a/src/components/style/selectors.rs
+++ b/src/components/style/selectors.rs
@@ -309,6 +309,7 @@ fn parse_one_simple_selector(iter: &mut Iter, namespaces: &NamespaceMap, inside_
             match iter.next() {
                 Some(Ident(name)) => match parse_simple_pseudo_class(name) {
                     None => {
+                        // FIXME: Workaround for https://github.com/mozilla/rust/issues/10683
                         let name_lower = name.to_ascii_lower(); 
                         match name_lower.as_slice() {
                             // Supported CSS 2.1 pseudo-elements only.
@@ -446,6 +447,7 @@ fn parse_attribute_selector(content: ~[ComponentValue], namespaces: &NamespaceMa
 
 
 fn parse_simple_pseudo_class(name: &str) -> Option<SimpleSelector> {
+    // FIXME: Workaround for https://github.com/mozilla/rust/issues/10683
     let name_lower = name.to_ascii_lower(); 
     match name_lower.as_slice() {
         "any-link" => Some(AnyLink),
@@ -467,6 +469,7 @@ fn parse_simple_pseudo_class(name: &str) -> Option<SimpleSelector> {
 fn parse_functional_pseudo_class(name: ~str, arguments: ~[ComponentValue],
                                  namespaces: &NamespaceMap, inside_negation: bool)
                                  -> Option<SimpleSelector> {
+    // FIXME: Workaround for https://github.com/mozilla/rust/issues/10683
     let name_lower = name.to_ascii_lower(); 
     match name_lower.as_slice() {
 //        "lang" => parse_lang(arguments),
@@ -481,6 +484,7 @@ fn parse_functional_pseudo_class(name: ~str, arguments: ~[ComponentValue],
 
 
 fn parse_pseudo_element(name: ~str) -> Option<PseudoElement> {
+    // FIXME: Workaround for https://github.com/mozilla/rust/issues/10683
     let name_lower = name.to_ascii_lower();  
     match name_lower.as_slice() {
         // All supported pseudo-elements