diff --git a/js/src/vm/RegExpObject.cpp b/js/src/vm/RegExpObject.cpp
index 61baadef81..00d4222272 100644
--- a/js/src/vm/RegExpObject.cpp
+++ b/js/src/vm/RegExpObject.cpp
@@ -187,11 +187,6 @@ IsMarkingTrace(JSTracer* trc)
 void
 RegExpObject::trace(JSTracer* trc)
 {
-    // When marking the object normally we have the option of unlinking the
-    // object from its RegExpShared so that the RegExpShared may be collected.
-    if (IsMarkingTrace(trc) && !zone()->isPreservingCode())
-        sharedRef() = nullptr;
-
     TraceNullableEdge(trc, &sharedRef(), "RegExpObject shared");
 }
 
diff --git a/js/src/vm/RegExpObject.h b/js/src/vm/RegExpObject.h
index 4f35908087..f4adf76e83 100644
--- a/js/src/vm/RegExpObject.h
+++ b/js/src/vm/RegExpObject.h
@@ -464,7 +464,7 @@ class RegExpObject : public NativeObject
 
     void setShared(RegExpShared& shared) {
         MOZ_ASSERT(!hasShared());
-        sharedRef() = &shared;
+        sharedRef().init(&shared);
     }
 
     static void trace(JSTracer* trc, JSObject* obj);
@@ -490,9 +490,9 @@ class RegExpObject : public NativeObject
     static MOZ_MUST_USE bool createShared(JSContext* cx, Handle<RegExpObject*> regexp,
                                           MutableHandleRegExpShared shared);
 
-    ReadBarriered<RegExpShared*>& sharedRef() {
+    PreBarriered<RegExpShared*>& sharedRef() {
         auto& ref = NativeObject::privateRef(PRIVATE_SLOT);
-        return reinterpret_cast<ReadBarriered<RegExpShared*>&>(ref);
+        return reinterpret_cast<PreBarriered<RegExpShared*>&>(ref);
     }
 
     /* Call setShared in preference to setPrivate. */