diff --git a/dom/sms/interfaces/nsIDOMSmsRequest.idl b/dom/sms/interfaces/nsIDOMSmsRequest.idl
index e32f34e0bd6..8e7cd3dda46 100644
--- a/dom/sms/interfaces/nsIDOMSmsRequest.idl
+++ b/dom/sms/interfaces/nsIDOMSmsRequest.idl
@@ -5,14 +5,15 @@
 #include "nsIDOMEventTarget.idl"
 
 interface nsIDOMEventListener;
+interface nsIDOMDOMError;
 
-[scriptable, builtinclass, uuid(1b24469d-cfb7-4667-aaf0-c1d17289ae7c)]
+[scriptable, builtinclass, uuid(a41765d7-6e5d-4458-b08a-993c2c60ce88)]
 interface nsIDOMMozSmsRequest : nsIDOMEventTarget
 {
   // Returns whether "processing" or "done".
   readonly attribute DOMString           readyState;
   // Can be null.
-  readonly attribute DOMString           error;
+  readonly attribute nsIDOMDOMError      error;
   // Can be bool, nsIDOMSmsMessage, nsIDOMSmsIterator or null.
   readonly attribute jsval               result;
 
diff --git a/dom/sms/src/SmsRequest.cpp b/dom/sms/src/SmsRequest.cpp
index 1913630c964..2277bda7306 100644
--- a/dom/sms/src/SmsRequest.cpp
+++ b/dom/sms/src/SmsRequest.cpp
@@ -11,6 +11,7 @@
 #include "nsIDOMSmsCursor.h"
 #include "nsISmsRequestManager.h"
 #include "SmsManager.h"
+#include "mozilla/dom/DOMError.h"
 
 DOMCI_DATA(MozSmsRequest, mozilla::dom::sms::SmsRequest)
 
@@ -26,6 +27,7 @@ NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(SmsRequest,
   NS_CYCLE_COLLECTION_TRAVERSE_EVENT_HANDLER(success)
   NS_CYCLE_COLLECTION_TRAVERSE_EVENT_HANDLER(error)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE_NSCOMPTR(mCursor)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE_NSCOMPTR(mError)
 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
 
 NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN_INHERITED(SmsRequest,
@@ -37,6 +39,7 @@ NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN_INHERITED(SmsRequest,
   NS_CYCLE_COLLECTION_UNLINK_EVENT_HANDLER(success)
   NS_CYCLE_COLLECTION_UNLINK_EVENT_HANDLER(error)
   NS_IMPL_CYCLE_COLLECTION_UNLINK_NSCOMPTR(mCursor)
+  NS_IMPL_CYCLE_COLLECTION_UNLINK_NSCOMPTR(mError)
 NS_IMPL_CYCLE_COLLECTION_UNLINK_END
 
 NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN_INHERITED(SmsRequest,
@@ -62,7 +65,6 @@ NS_IMPL_EVENT_HANDLER(SmsRequest, error)
 SmsRequest::SmsRequest(SmsManager* aManager)
   : mResult(JSVAL_VOID)
   , mResultRooted(false)
-  , mError(nsISmsRequestManager::SUCCESS_NO_ERROR)
   , mDone(false)
 {
   BindToOwner(aManager);
@@ -80,8 +82,7 @@ SmsRequest::Reset()
 {
   NS_ASSERTION(mDone, "mDone should be true if we try to reset!");
   NS_ASSERTION(mResult != JSVAL_VOID, "mResult should be set if we try to reset!");
-  NS_ASSERTION(mError == nsISmsRequestManager::SUCCESS_NO_ERROR,
-               "There should be no error if we try to reset!");
+  NS_ASSERTION(!mError, "There should be no error if we try to reset!");
 
   if (mResultRooted) {
     UnrootResult();
@@ -117,8 +118,7 @@ void
 SmsRequest::SetSuccess(bool aResult)
 {
   NS_PRECONDITION(!mDone, "mDone shouldn't have been set to true already!");
-  NS_PRECONDITION(mError == nsISmsRequestManager::SUCCESS_NO_ERROR,
-                  "mError shouldn't have been set!");
+  NS_PRECONDITION(!mError, "mError shouldn't have been set!");
   NS_PRECONDITION(mResult == JSVAL_NULL, "mResult shouldn't have been set!");
 
   mResult.setBoolean(aResult);
@@ -144,8 +144,7 @@ bool
 SmsRequest::SetSuccessInternal(nsISupports* aObject)
 {
   NS_PRECONDITION(!mDone, "mDone shouldn't have been set to true already!");
-  NS_PRECONDITION(mError == nsISmsRequestManager::SUCCESS_NO_ERROR,
-                  "mError shouldn't have been set!");
+  NS_PRECONDITION(!mError, "mError shouldn't have been set!");
   NS_PRECONDITION(mResult == JSVAL_VOID, "mResult shouldn't have been set!");
 
   nsresult rv;
@@ -185,13 +184,30 @@ void
 SmsRequest::SetError(PRInt32 aError)
 {
   NS_PRECONDITION(!mDone, "mDone shouldn't have been set to true already!");
-  NS_PRECONDITION(mError == nsISmsRequestManager::SUCCESS_NO_ERROR,
-                  "mError shouldn't have been set!");
+  NS_PRECONDITION(!mError, "mError shouldn't have been set!");
   NS_PRECONDITION(mResult == JSVAL_VOID, "mResult shouldn't have been set!");
+  NS_PRECONDITION(aError != nsISmsRequestManager::SUCCESS_NO_ERROR,
+                  "Can't call SetError() with SUCCESS_NO_ERROR!");
 
   mDone = true;
-  mError = aError;
   mCursor = nsnull;
+
+  switch (aError) {
+    case nsISmsRequestManager::NO_SIGNAL_ERROR:
+      mError = DOMError::CreateWithName(NS_LITERAL_STRING("NoSignalError"));
+      break;
+    case nsISmsRequestManager::NOT_FOUND_ERROR:
+      mError = DOMError::CreateWithName(NS_LITERAL_STRING("NotFoundError"));
+      break;
+    case nsISmsRequestManager::UNKNOWN_ERROR:
+      mError = DOMError::CreateWithName(NS_LITERAL_STRING("UnknownError"));
+      break;
+    case nsISmsRequestManager::INTERNAL_ERROR:
+      mError = DOMError::CreateWithName(NS_LITERAL_STRING("InternalError"));
+      break;
+    default: // SUCCESS_NO_ERROR is handled above.
+      MOZ_ASSERT(false, "Unknown error value.");
+  }
 }
 
 NS_IMETHODIMP
@@ -207,39 +223,13 @@ SmsRequest::GetReadyState(nsAString& aReadyState)
 }
 
 NS_IMETHODIMP
-SmsRequest::GetError(nsAString& aError)
+SmsRequest::GetError(nsIDOMDOMError** aError)
 {
-  if (!mDone) {
-    NS_ASSERTION(mError == nsISmsRequestManager::SUCCESS_NO_ERROR,
-                 "There should be no error if the request is still processing!");
-
-    SetDOMStringToNull(aError);
-    return NS_OK;
-  }
-
-  NS_ASSERTION(mError == nsISmsRequestManager::SUCCESS_NO_ERROR ||
-               mResult == JSVAL_VOID,
+  NS_ASSERTION(mDone || !mError, "mError should be null when pending");
+  NS_ASSERTION(!mError || mResult == JSVAL_VOID,
                "mResult should be void when there is an error!");
 
-  switch (mError) {
-    case nsISmsRequestManager::SUCCESS_NO_ERROR:
-      SetDOMStringToNull(aError);
-      break;
-    case nsISmsRequestManager::NO_SIGNAL_ERROR:
-      aError.AssignLiteral("NoSignalError");
-      break;
-    case nsISmsRequestManager::NOT_FOUND_ERROR:
-      aError.AssignLiteral("NotFoundError");
-      break;
-    case nsISmsRequestManager::UNKNOWN_ERROR:
-      aError.AssignLiteral("UnknownError");
-      break;
-    case nsISmsRequestManager::INTERNAL_ERROR:
-      aError.AssignLiteral("InternalError");
-      break;
-    default:
-      MOZ_ASSERT(false, "Unknown error value.");
-  }
+  NS_IF_ADDREF(*aError = mError);
 
   return NS_OK;
 }
diff --git a/dom/sms/src/SmsRequest.h b/dom/sms/src/SmsRequest.h
index 86f43c4216c..3913b78a4ac 100644
--- a/dom/sms/src/SmsRequest.h
+++ b/dom/sms/src/SmsRequest.h
@@ -85,8 +85,8 @@ private:
 
   jsval     mResult;
   bool      mResultRooted;
-  PRInt32   mError;
   bool      mDone;
+  nsCOMPtr<nsIDOMDOMError> mError;
   nsCOMPtr<nsIDOMMozSmsCursor> mCursor;
 
   NS_DECL_EVENT_HANDLER(success)