diff --git a/components/style/gecko_bindings/bindings.rs b/components/style/gecko_bindings/bindings.rs
index 5b030075966..6aab0a41d7d 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);
diff --git a/components/style/gecko_bindings/sugar/ns_css_value.rs b/components/style/gecko_bindings/sugar/ns_css_value.rs
index a14ea0efb07..e2ff4ceab30 100644
--- a/components/style/gecko_bindings/sugar/ns_css_value.rs
+++ b/components/style/gecko_bindings/sugar/ns_css_value.rs
@@ -134,6 +134,11 @@ impl nsCSSValue {
         self.set_string_internal(s, nsCSSUnit::eCSSUnit_Ident)
     }
 
+    /// Set to an atom identifier value
+    pub fn set_atom_ident(&mut self, s: Atom) {
+        unsafe { bindings::Gecko_CSSValue_SetAtomIdent(self, s.into_addrefed()) }
+    }
+
     /// Set to a font format
     pub fn set_font_format(&mut self, s: &str) {
         self.set_string_internal(s, nsCSSUnit::eCSSUnit_Font_Format);
diff --git a/components/style/gecko_string_cache/mod.rs b/components/style/gecko_string_cache/mod.rs
index 63ba6d7977c..741a4a3e534 100644
--- a/components/style/gecko_string_cache/mod.rs
+++ b/components/style/gecko_string_cache/mod.rs
@@ -226,6 +226,14 @@ impl Atom {
         }
     }
 
+    /// Convert this atom into an addrefed nsIAtom pointer.
+    #[inline]
+    pub fn into_addrefed(self) -> *mut nsIAtom {
+        let ptr = self.as_ptr();
+        mem::forget(self);
+        ptr
+    }
+
     /// Return whether two atoms are ASCII-case-insensitive matches
     pub fn eq_ignore_ascii_case(&self, other: &Self) -> bool {
         let a = self.as_slice();
diff --git a/components/style/properties/gecko.mako.rs b/components/style/properties/gecko.mako.rs
index 69365b98082..f6fb7b95709 100644
--- a/components/style/properties/gecko.mako.rs
+++ b/components/style/properties/gecko.mako.rs
@@ -4152,7 +4152,7 @@ clip-path
                             let mut array = unsafe { &mut **self.gecko.mContents[i].mContent.mCounters.as_mut() };
                             array[0].set_string(&name);
                             // When we support <custom-ident> values for list-style-type this will need to be updated
-                            array[1].set_ident(&style.to_css_string());
+                            array[1].set_atom_ident(style.to_css_string().into());
                         }
                         ContentItem::Counters(name, sep, style) => {
                             unsafe {
@@ -4163,7 +4163,7 @@ clip-path
                             array[0].set_string(&name);
                             array[1].set_string(&sep);
                             // When we support <custom-ident> values for list-style-type this will need to be updated
-                            array[2].set_ident(&style.to_css_string());
+                            array[2].set_atom_ident(style.to_css_string().into());
                         }
                         ContentItem::Url(url) => {
                             unsafe { bindings::Gecko_SetContentDataImage(&mut self.gecko.mContents[i], url.for_ffi()) }