diff --git a/layout/style/ServoBindings.toml b/layout/style/ServoBindings.toml
--- a/layout/style/ServoBindings.toml
+++ b/layout/style/ServoBindings.toml
@@ -296,16 +296,17 @@ opaque-types = [
     "std::atomic",
     "std::atomic___base",
     "std::tuple.*", # Causes "Cannot find type _Pred in this scope" error on mac, like rust-skia#571
     "std::.*::tuple.*",
 
     "mozilla::dom::Touch",
     "mozilla::dom::Sequence",
     "mozilla::SmallPointerArray",
+    "mozilla::SmallPointerArray_Element",
     "mozilla::dom::Optional",
     "mozilla::dom::OwningNodeOrString_Value",
     "mozilla::dom::Nullable",
     "mozilla::external::AtomicRefCounted",
     "RefPtr_Proxy",
     "RefPtr_Proxy_member_function",
     "nsAutoPtr_Proxy",
     "nsAutoPtr_Proxy_member_function",