--- a/accessible/ipc/DocAccessibleParent.cpp
+++ b/accessible/ipc/DocAccessibleParent.cpp
@@ -406,23 +406,18 @@ DocAccessibleParent::RecvBindChildDoc(PD
 
 ipc::IPCResult
 DocAccessibleParent::AddChildDoc(DocAccessibleParent* aChildDoc,
                                  uint64_t aParentID, bool aCreating)
 {
   // We do not use GetAccessible here because we want to be sure to not get the
   // document it self.
   ProxyEntry* e = mAccessibles.GetEntry(aParentID);
-  if (!e) {
-#ifdef DEBUG
+  if (!e)
     return IPC_FAIL(this, "binding to nonexistant proxy!");
-#else
-    return IPC_OK();
-#endif
-  }
 
   ProxyAccessible* outerDoc = e->mProxy;
   MOZ_ASSERT(outerDoc);
 
   // OuterDocAccessibles are expected to only have a document as a child.
   // However for compatibility we tolerate replacing one document with another
   // here.
   if (outerDoc->ChildrenCount() > 1 ||