diff --git a/layout/style/nsCSSRuleProcessor.cpp b/layout/style/nsCSSRuleProcessor.cpp
index 1ecf80bc52..ff3661c73d 100644
--- a/layout/style/nsCSSRuleProcessor.cpp
+++ b/layout/style/nsCSSRuleProcessor.cpp
@@ -680,7 +680,11 @@ void RuleHash::EnumerateAllRules(Element* aElement, ElementDependentRuleProcesso
       aData->mTreeMatchContext.mAncestorFilter.HasFilter() ?
         &aData->mTreeMatchContext.mAncestorFilter : nullptr;
 #ifdef DEBUG
-    if (filter) {
+    bool isRestricted = (aData->mTreeMatchContext.mShadowHosts.Length() > 0 ||
+      aData->mTreeMatchContext.mRestrictToSlottedPseudo ||
+      aData->mTreeMatchContext.mOnlyMatchHostPseudo ||
+      aData->mTreeMatchContext.mForAssignedSlot);
+    if (filter && !isRestricted) {
       filter->AssertHasAllAncestors(aElement);
     }
 #endif