diff --git a/dom/xbl/nsBindingManager.cpp b/dom/xbl/nsBindingManager.cpp
index 39d631d78560..faed4edb85b7 100644
--- a/dom/xbl/nsBindingManager.cpp
+++ b/dom/xbl/nsBindingManager.cpp
@@ -740,22 +740,23 @@ nsBindingManager::WalkAllRules(nsIStyleRuleProcessor::EnumFunc aFunc,
   });
 }
 
-bool
-nsBindingManager::MediumFeaturesChanged(nsPresContext* aPresContext)
+nsresult
+nsBindingManager::MediumFeaturesChanged(nsPresContext* aPresContext,
+                                        bool* aRulesChanged)
 {
-  bool rulesChanged = false;
+  *aRulesChanged = false;
   RefPtr<nsPresContext> presContext = aPresContext;
 
-  EnumerateBoundContentBindings([=, &rulesChanged](nsXBLBinding* aBinding) {
+  EnumerateBoundContentBindings([=](nsXBLBinding* aBinding) {
     nsIStyleRuleProcessor* ruleProcessor =
       aBinding->PrototypeBinding()->GetRuleProcessor();
     if (ruleProcessor) {
       bool thisChanged = ruleProcessor->MediumFeaturesChanged(presContext);
-      rulesChanged = rulesChanged || thisChanged;
+      *aRulesChanged = *aRulesChanged || thisChanged;
     }
   });
 
-  return rulesChanged;
+  return NS_OK;
 }
 
 void
diff --git a/dom/xbl/nsBindingManager.h b/dom/xbl/nsBindingManager.h
index cde7889e4454..b5d9b207c870 100644
--- a/dom/xbl/nsBindingManager.h
+++ b/dom/xbl/nsBindingManager.h
@@ -135,7 +135,8 @@ public:
    * the characteristics of the medium, and return whether this rule
    * processor's rules have changed (e.g., because of media queries).
    */
-  bool MediumFeaturesChanged(nsPresContext* aPresContext);
+  nsresult MediumFeaturesChanged(nsPresContext* aPresContext,
+                                 bool* aRulesChanged);
 
   void AppendAllSheets(nsTArray<mozilla::StyleSheet*>& aArray);
 
diff --git a/layout/style/nsStyleSet.cpp b/layout/style/nsStyleSet.cpp
index 01d5fae91a8b..901a8d941b39 100644
--- a/layout/style/nsStyleSet.cpp
+++ b/layout/style/nsStyleSet.cpp
@@ -2686,8 +2686,8 @@ nsStyleSet::MediumFeaturesChanged(bool aViewportChanged)
   }
 
   if (mBindingManager) {
-    bool thisChanged =
-      mBindingManager->MediumFeaturesChanged(presContext);
+    bool thisChanged = false;
+    mBindingManager->MediumFeaturesChanged(presContext, &thisChanged);
     stylesChanged = stylesChanged || thisChanged;
   }