diff --git a/components/style/gecko_bindings/sugar/refptr.rs b/components/style/gecko_bindings/sugar/refptr.rs
index 5019663a580..10c9e627699 100644
--- a/components/style/gecko_bindings/sugar/refptr.rs
+++ b/components/style/gecko_bindings/sugar/refptr.rs
@@ -4,6 +4,7 @@
 
 //! A rust helper to ease the use of Gecko's refcounted types.
 
+use Atom;
 use gecko_bindings::{structs, bindings};
 use gecko_bindings::sugar::ownership::HasArcFFI;
 use servo_arc::Arc;
@@ -320,3 +321,17 @@ impl_threadsafe_refcount!(
     bindings::Gecko_AddRefSheetLoadDataHolderArbitraryThread,
     bindings::Gecko_ReleaseSheetLoadDataHolderArbitraryThread
 );
+
+#[inline]
+unsafe fn addref_atom(atom: *mut structs::nsAtom) {
+    mem::forget(Atom::from_raw(atom));
+}
+#[inline]
+unsafe fn release_atom(atom: *mut structs::nsAtom) {
+    let _ = Atom::from_addrefed(atom);
+}
+impl_threadsafe_refcount!(
+    structs::nsAtom,
+    addref_atom,
+    release_atom
+);
diff --git a/components/style/properties/gecko.mako.rs b/components/style/properties/gecko.mako.rs
index b4411e1ea8b..13d93b0a144 100644
--- a/components/style/properties/gecko.mako.rs
+++ b/components/style/properties/gecko.mako.rs
@@ -3274,10 +3274,7 @@ fn static_assert() {
             self.gecko.mTransitions.ensure_len(v.len());
             self.gecko.mTransitionPropertyCount = v.len() as u32;
             for (servo, gecko) in v.zip(self.gecko.mTransitions.iter_mut()) {
-                if !gecko.mUnknownProperty.mRawPtr.is_null() {
-                    unsafe { Atom::from_addrefed(gecko.mUnknownProperty.mRawPtr) };
-                    gecko.mUnknownProperty.mRawPtr = ptr::null_mut();
-                }
+                unsafe { gecko.mUnknownProperty.clear() };
 
                 match servo {
                     TransitionProperty::Unsupported(ident) => {
@@ -3355,10 +3352,7 @@ fn static_assert() {
 
         for (index, transition) in self.gecko.mTransitions.iter_mut().enumerate().take(count as usize) {
             transition.mProperty = other.gecko.mTransitions[index].mProperty;
-            if !transition.mUnknownProperty.mRawPtr.is_null() {
-                unsafe { Atom::from_addrefed(transition.mUnknownProperty.mRawPtr) };
-                transition.mUnknownProperty.mRawPtr = ptr::null_mut();
-            }
+            unsafe { transition.mUnknownProperty.clear() };
             if transition.mProperty == eCSSProperty_UNKNOWN ||
                transition.mProperty == eCSSPropertyExtra_variable {
                 let atom = other.gecko.mTransitions[index].mUnknownProperty.mRawPtr;