diff --git a/src/compiler/heap-refs.h b/src/compiler/heap-refs.h
index c03ae3a109..0379689ccd 100644
--- a/src/compiler/heap-refs.h
+++ b/src/compiler/heap-refs.h
@@ -64,6 +64,7 @@ enum class OddballType : uint8_t {
   /* Subtypes of String */                          \
   V(InternalizedString)                             \
   /* Subtypes of Name */                            \
+  V(String)                                         \
   V(Symbol)                                         \
   /* Subtypes of HeapObject */                      \
   V(AccessorInfo)                                   \
@@ -93,8 +94,6 @@ enum class OddballType : uint8_t {
   V(BytecodeArray)                            \
   V(FixedArray)                               \
   V(FixedDoubleArray)                         \
-  /* Subtypes of Name */                      \
-  V(String)                                   \
   /* Subtypes of JSReceiver */                \
   V(JSObject)                                 \
   /* Subtypes of HeapObject */                \
diff --git a/src/compiler/js-heap-broker.cc b/src/compiler/js-heap-broker.cc
index 9ed0875b77..6696595784 100644
--- a/src/compiler/js-heap-broker.cc
+++ b/src/compiler/js-heap-broker.cc
@@ -812,7 +812,9 @@ StringData::StringData(JSHeapBroker* broker, ObjectData** storage,
       to_number_(TryStringToDouble(broker->local_isolate(), object)),
       is_external_string_(object->IsExternalString()),
       is_seq_string_(object->IsSeqString()),
-      chars_as_strings_(broker->zone()) {}
+      chars_as_strings_(broker->zone()) {
+  DCHECK(!FLAG_turbo_direct_heap_access);
+}
 
 class InternalizedStringData : public StringData {
  public: