diff --git a/ets2panda/checker/ets/object.cpp b/ets2panda/checker/ets/object.cpp
index 82f486c79ec36b88168d8a7e19e117f1e46cefbd..88a29aac6f0959a2a2f6bde151c4011bda6b9c8b 100644
--- a/ets2panda/checker/ets/object.cpp
+++ b/ets2panda/checker/ets/object.cpp
@@ -1277,11 +1277,7 @@ void ETSChecker::CheckClassDefinition(ir::ClassDefinition *classDef)
         classType->SuperType()->GetDeclNode()->Check(this);
     }
 
-    if (classType->GetDeclNode() != classDef) {
-        ES2PANDA_ASSERT(IsAnyError());
-        classDef->SetTsType(GlobalTypeError());
-        return;
-    }
+    ES2PANDA_ASSERT(classType->GetDeclNode() == classDef);
 
     auto newStatus = checker::CheckerStatus::IN_CLASS;
     if (Context().ContainingClass() != classType) {
diff --git a/ets2panda/checker/ets/typeCreation.cpp b/ets2panda/checker/ets/typeCreation.cpp
index 959fcad7731532ffdfb72a35ebfbf334621adbbd..7fa9f971b4a12fb575f099b7a42b5b3625f52f59 100644
--- a/ets2panda/checker/ets/typeCreation.cpp
+++ b/ets2panda/checker/ets/typeCreation.cpp
@@ -287,10 +287,12 @@ static ETSObjectType *InitializeGlobalBuiltinObjectType(ETSChecker *checker, Glo
 
     auto const setType = [checker](GlobalTypeId slotId, Type *type) {
         auto &slot = checker->GetGlobalTypesHolder()->GlobalTypes()[helpers::ToUnderlying(slotId)];
-        if (slot == nullptr) {
-            slot = type;
+        if (UNLIKELY(slot != nullptr)) {
+            ES2PANDA_ASSERT(checker->IsAnyError());
+            return type;
         }
-        return slot;
+        slot = type;
+        return type;
     };
 
     auto *const programAllocator = checker->ProgramAllocator();
@@ -374,8 +376,8 @@ ETSObjectType *ETSChecker::CreateETSObjectType(ir::AstNode *declNode, ETSObjectF
                                                                     Relation());
         }
     } else if (internalName == compiler::Signatures::BUILTIN_ARRAY) {
-        objectType = ProgramAllocator()->New<ETSResizableArrayType>(ProgramAllocator(), name,
-                                                                    std::make_tuple(declNode, flags, Relation()));
+        objectType = ProgramAllocator()->New<ETSResizableArrayType>(
+            ProgramAllocator(), name, std::make_tuple(declNode, flags | ETSObjectFlags::BUILTIN_ARRAY, Relation()));
     } else {
         objectType = ProgramAllocator()->New<ETSObjectType>(ProgramAllocator(), name, internalName,
                                                             std::make_tuple(declNode, flags, Relation()));
diff --git a/ets2panda/checker/types/ets/etsResizableArrayType.h b/ets2panda/checker/types/ets/etsResizableArrayType.h
index 90936ceadfbcb45ac54ccc707dc04d294f067d07..c9b10498a8846d39f5e10a2a76989e3075edffdd 100644
--- a/ets2panda/checker/types/ets/etsResizableArrayType.h
+++ b/ets2panda/checker/types/ets/etsResizableArrayType.h
@@ -28,6 +28,7 @@ public:
                         ETSObjectFlags::CLASS | ETSObjectFlags::BUILTIN_ARRAY | ETSObjectFlags::RESOLVED_SUPER),
           element_(nullptr)
     {
+        ES2PANDA_ASSERT(IsETSResizableArrayType());
         SetSuperType(super);
     }
 
@@ -35,6 +36,7 @@ public:
                                    std::tuple<ir::AstNode *, ETSObjectFlags, TypeRelation *> info)
         : ETSObjectType(allocator, name, compiler::Signatures::BUILTIN_ARRAY, info), element_(nullptr)
     {
+        ES2PANDA_ASSERT(IsETSResizableArrayType());
     }
 
     explicit ETSResizableArrayType(ThreadSafeArenaAllocator *allocator, ETSObjectType *super, TypeRelation *relation,
@@ -46,6 +48,7 @@ public:
                               relation)),
           element_(element)
     {
+        ES2PANDA_ASSERT(IsETSResizableArrayType());
         SetSuperType(super);
         variable_ = super->Variable();
     }