--- a/layout/style/ServoStyleSet.cpp
+++ b/layout/style/ServoStyleSet.cpp
@@ -165,20 +165,19 @@ ServoStyleSet::GetContext(nsIContent* aC
                           nsStyleContext* aParentContext,
                           nsIAtom* aPseudoTag,
                           CSSPseudoElementType aPseudoType,
                           LazyComputeBehavior aMayCompute)
 {
   MOZ_ASSERT(aContent->IsElement());
   Element* element = aContent->AsElement();
 
-
-  PreTraverseSync();
   RefPtr<ServoComputedValues> computedValues;
   if (aMayCompute == LazyComputeBehavior::Allow) {
+    PreTraverseSync();
     computedValues = ResolveStyleLazily(element, nullptr);
   } else {
     computedValues = ResolveServoStyle(element);
   }
 
   MOZ_ASSERT(computedValues);
   return GetContext(computedValues.forget(), aParentContext, aPseudoTag, aPseudoType,
                     element);