diff --git a/js/public/GCAPI.h b/js/public/GCAPI.h
index 50700b715ff9..58178a0f60ba 100644
--- a/js/public/GCAPI.h
+++ b/js/public/GCAPI.h
@@ -524,20 +524,6 @@ class JS_PUBLIC_API(AutoAssertNoAlloc)
 
 
 
-class JS_PUBLIC_API(AutoAssertOnBarrier)
-{
-    JSContext* context;
-    bool prev;
-
-  public:
-    explicit AutoAssertOnBarrier(JSContext* cx);
-    ~AutoAssertOnBarrier();
-};
-
-
-
-
-
 
 
 
@@ -623,7 +609,6 @@ ExposeGCThingToActiveJS(JS::GCCellPtr thing)
     if (IsInsideNursery(thing.asCell()))
         return;
     JS::shadow::Runtime* rt = detail::GetGCThingRuntime(thing.unsafeAsUIntPtr());
-    MOZ_DIAGNOSTIC_ASSERT(rt->allowGCBarriers());
     if (IsIncrementalBarrierNeededOnTenuredGCThing(rt, thing))
         JS::IncrementalReferenceBarrier(thing);
     else if (JS::GCThingIsMarkedGray(thing))
@@ -634,7 +619,6 @@ static MOZ_ALWAYS_INLINE void
 MarkGCThingAsLive(JSRuntime* aRt, JS::GCCellPtr thing)
 {
     JS::shadow::Runtime* rt = JS::shadow::Runtime::asShadowRuntime(aRt);
-    MOZ_DIAGNOSTIC_ASSERT(rt->allowGCBarriers());
     
 
 
diff --git a/js/src/jsgc.cpp b/js/src/jsgc.cpp
index bc322f15eab9..650fe1d8c92c 100644
--- a/js/src/jsgc.cpp
+++ b/js/src/jsgc.cpp
@@ -7013,20 +7013,6 @@ JS::AutoAssertOnGC::~AutoAssertOnGC()
     }
 }
 
-JS::AutoAssertOnBarrier::AutoAssertOnBarrier(JSContext* cx)
-  : context(cx),
-    prev(cx->runtime()->allowGCBarriers())
-{
-    context->runtime()->allowGCBarriers_ = false;
-}
-
-JS::AutoAssertOnBarrier::~AutoAssertOnBarrier()
-{
-    MOZ_ASSERT(!context->runtime()->allowGCBarriers_);
-    context->runtime()->allowGCBarriers_ = prev;
-}
-
-#ifdef DEBUG
 JS::AutoAssertNoAlloc::AutoAssertNoAlloc(JSContext* cx)
   : gc(nullptr)
 {
diff --git a/js/src/jspubtd.h b/js/src/jspubtd.h
index 812c4a1b36c0..8a1b2507d9d5 100644
--- a/js/src/jspubtd.h
+++ b/js/src/jspubtd.h
@@ -131,7 +131,6 @@ class StoreBuffer;
 namespace JS {
 
 class JS_PUBLIC_API(AutoEnterCycleCollection);
-class JS_PUBLIC_API(AutoAssertOnBarrier);
 struct PropertyDescriptor;
 
 typedef void (*OffThreadCompileCallback)(void* token, void* callbackData);
@@ -154,17 +153,11 @@ struct Runtime
     friend class JS::AutoEnterCycleCollection;
     JS::HeapState heapState_;
 
-    
-    
-    bool allowGCBarriers_;
-    friend class JS::AutoAssertOnBarrier;
-
     js::gc::StoreBuffer* gcStoreBufferPtr_;
 
   public:
     Runtime()
       : heapState_(JS::HeapState::Idle)
-      , allowGCBarriers_(true)
       , gcStoreBufferPtr_(nullptr)
     {}
 
@@ -176,8 +169,6 @@ struct Runtime
         return heapState_ == JS::HeapState::CycleCollecting;
     }
 
-    bool allowGCBarriers() const { return allowGCBarriers_; }
-
     js::gc::StoreBuffer* gcStoreBufferPtr() { return gcStoreBufferPtr_; }
 
     static JS::shadow::Runtime* asShadowRuntime(JSRuntime* rt) {