diff --git a/components/style/gecko_bindings/bindings.rs b/components/style/gecko_bindings/bindings.rs
index 1553536b706..03abd4d96d5 100644
--- a/components/style/gecko_bindings/bindings.rs
+++ b/components/style/gecko_bindings/bindings.rs
@@ -1139,6 +1139,10 @@ extern "C" {
                                             atom: *mut nsIAtom,
                                             unit: nsCSSUnit);
 }
+extern "C" {
+    pub fn Gecko_CSSValue_SetAtomIdent(css_value: nsCSSValueBorrowedMut,
+                                       atom: *mut nsIAtom);
+}
 extern "C" {
     pub fn Gecko_CSSValue_SetArray(css_value: nsCSSValueBorrowedMut,
                                    len: i32);