--- a/js/src/frontend/BinSource.cpp
+++ b/js/src/frontend/BinSource.cpp
@@ -45,26 +45,26 @@ public:
     ScopeData(JSContext* cx)
       : letNames(cx)
       , constNames(cx)
       , varNames(cx)
       , capturedNames(cx)
     { }
     bool isSome() const {
         if (hasDirectEval.isSome()) {
-            MOZ_ASSERT(letNames.isSome());
-            MOZ_ASSERT(constNames.isSome());
-            MOZ_ASSERT(varNames.isSome());
-            MOZ_ASSERT(capturedNames.isSome());
+            MOZ_ASSERT(letNames->isSome());
+            MOZ_ASSERT(constNames->isSome());
+            MOZ_ASSERT(varNames->isSome());
+            MOZ_ASSERT(capturedNames->isSome());
             return true;
         } else {
-            MOZ_ASSERT(!letNames.isSome());
-            MOZ_ASSERT(!constNames.isSome());
-            MOZ_ASSERT(!varNames.isSome());
-            MOZ_ASSERT(!capturedNames.isSome());
+            MOZ_ASSERT(!letNames->isSome());
+            MOZ_ASSERT(!constNames->isSome());
+            MOZ_ASSERT(!varNames->isSome());
+            MOZ_ASSERT(!capturedNames->isSome());
             return false;
         }
     }
     Maybe<bool> hasDirectEval;
     Rooted<Maybe<Names>> letNames;
     Rooted<Maybe<Names>> constNames;
     Rooted<Maybe<Names>> varNames;
     Rooted<Maybe<NameBag>> capturedNames;
@@ -1980,10 +1980,12 @@ ASTReader::raiseError() {
 }
 
 void
 TraceBinParser(JSTracer* trc, AutoGCRooter* parser)
 {
     static_cast<ASTReader*>(parser)->trace(trc);
 }
 
+static ASTReader foo(nullptr, *static_cast<LifoAlloc*>(nullptr));
+
 } // namespace frontend
 } // namespace js