--- a/layout/style/ServoStyleSet.cpp
+++ b/layout/style/ServoStyleSet.cpp
@@ -501,17 +501,19 @@ ServoStyleSet::StyleDocument(bool aLeave
     ClearDirtyBits(root);
   }
 }
 
 void
 ServoStyleSet::StyleNewSubtree(nsIContent* aContent)
 {
   MOZ_ASSERT(aContent->IsDirtyForServo());
-  Servo_RestyleSubtree(aContent, mRawSet.get());
+  if (aContent->IsElement() || aContent->IsNodeOfType(nsINode::eTEXT)) {
+    Servo_RestyleSubtree(aContent, mRawSet.get());
+  }
   ClearDirtyBits(aContent);
 }
 
 void
 ServoStyleSet::StyleNewChildren(nsIContent* aParent)
 {
   MOZ_ASSERT(aParent->HasDirtyDescendantsForServo());
   Servo_RestyleSubtree(aParent, mRawSet.get());