diff --git a/components/style/gecko_bindings/sugar/ns_t_array.rs b/components/style/gecko_bindings/sugar/ns_t_array.rs
index e3d4e5b86bd..04ba326c615 100644
--- a/components/style/gecko_bindings/sugar/ns_t_array.rs
+++ b/components/style/gecko_bindings/sugar/ns_t_array.rs
@@ -5,7 +5,7 @@
 //! Rust helpers for Gecko's nsTArray.
 
 use crate::gecko_bindings::bindings;
-use crate::gecko_bindings::structs::{nsTArray, nsTArrayHeader};
+use crate::gecko_bindings::structs::{nsTArray, nsTArrayHeader, CopyableTArray};
 use std::mem;
 use std::ops::{Deref, DerefMut};
 use std::slice;
@@ -128,3 +128,16 @@ impl<T> nsTArray<T> {
         self.iter_mut().zip(iter).for_each(|(r, v)| *r = v);
     }
 }
+
+impl<T> Deref for CopyableTArray<T> {
+    type Target = nsTArray<T>;
+    fn deref(&self) -> &Self::Target {
+        &self._base
+    }
+}
+
+impl<T> DerefMut for CopyableTArray<T> {
+    fn deref_mut(&mut self) -> &mut nsTArray<T> {
+        &mut self._base
+    }
+}