diff --git a/components/style/build_gecko.rs b/components/style/build_gecko.rs
index 9c13780b8da..fb464c1f7b2 100644
--- a/components/style/build_gecko.rs
+++ b/components/style/build_gecko.rs
@@ -235,6 +235,7 @@ mod bindings {
             .include(add_include("mozilla/Keyframe.h"))
             .include(add_include("mozilla/ServoElementSnapshot.h"))
             .include(add_include("mozilla/dom/Element.h"))
+            .include(add_include("mozilla/dom/NameSpaceConstants.h"))
             .include(add_include("mozilla/ServoBindings.h"))
             .include(add_include("nsMediaFeatures.h"))
             .include(add_include("nsMediaList.h"))
@@ -258,6 +259,7 @@ mod bindings {
             "BORDER_COLOR_.*",
             "BORDER_STYLE_.*",
             "mozilla::SERVO_PREF_.*",
+            "kNameSpaceID_.*",
         ];
         let whitelist = [
             "RawGecko.*",
diff --git a/components/style/gecko/wrapper.rs b/components/style/gecko/wrapper.rs
index 6456bfea90c..684e557dd26 100644
--- a/components/style/gecko/wrapper.rs
+++ b/components/style/gecko/wrapper.rs
@@ -25,12 +25,12 @@ use gecko::snapshot_helpers;
 use gecko_bindings::bindings;
 use gecko_bindings::bindings::{Gecko_DropStyleChildrenIterator, Gecko_MaybeCreateStyleChildrenIterator};
 use gecko_bindings::bindings::{Gecko_ElementState, Gecko_GetLastChild, Gecko_GetNextStyleChild};
-use gecko_bindings::bindings::{Gecko_GetServoDeclarationBlock, Gecko_IsHTMLElementInHTMLDocument};
 use gecko_bindings::bindings::{Gecko_IsLink, Gecko_IsRootElement, Gecko_MatchesElement};
 use gecko_bindings::bindings::{Gecko_IsUnvisitedLink, Gecko_IsVisitedLink, Gecko_Namespace};
 use gecko_bindings::bindings::{Gecko_SetNodeFlags, Gecko_UnsetNodeFlags};
 use gecko_bindings::bindings::Gecko_ClassOrClassList;
 use gecko_bindings::bindings::Gecko_GetAnimationRule;
+use gecko_bindings::bindings::Gecko_GetServoDeclarationBlock;
 use gecko_bindings::bindings::Gecko_GetStyleContext;
 use gecko_bindings::structs;
 use gecko_bindings::structs::{RawGeckoElement, RawGeckoNode};
@@ -88,6 +88,11 @@ impl<'ln> GeckoNode<'ln> {
         unsafe { &*self.0.mNodeInfo.mRawPtr }
     }
 
+    fn owner_doc(&self) -> &structs::nsIDocument {
+        debug_assert!(!self.node_info().mDocument.is_null());
+        unsafe { &*self.node_info().mDocument }
+    }
+
     fn first_child(&self) -> Option<GeckoNode<'ln>> {
         unsafe { self.0.mFirstChild.as_ref().map(GeckoNode::from_content) }
     }
@@ -565,9 +570,10 @@ impl<'le> ::selectors::Element for GeckoElement<'le> {
     }
 
     fn is_html_element_in_html_document(&self) -> bool {
-        unsafe {
-            Gecko_IsHTMLElementInHTMLDocument(self.0)
-        }
+        let node = self.as_node();
+        let node_info = node.node_info();
+        node_info.mInner.mNamespaceID == (structs::root::kNameSpaceID_XHTML as i32) &&
+        node.owner_doc().mType == structs::root::nsIDocument_Type::eHTML
     }
 }