diff --git a/internal/querycoordv2/meta/resource_manager.go b/internal/querycoordv2/meta/resource_manager.go
index 6b31da0571..1f403a5e7d 100644
--- a/internal/querycoordv2/meta/resource_manager.go
+++ b/internal/querycoordv2/meta/resource_manager.go
@@ -136,7 +136,7 @@ func (rm *ResourceManager) AddResourceGroup(rgName string) error {
 	}
 
 	if rm.groups[rgName] != nil {
-		return nil
+		return ErrRGAlreadyExist
 	}
 
 	if len(rm.groups) >= 1024 {
diff --git a/internal/querycoordv2/meta/resource_manager_test.go b/internal/querycoordv2/meta/resource_manager_test.go
index 287576691f..1735f4b520 100644
--- a/internal/querycoordv2/meta/resource_manager_test.go
+++ b/internal/querycoordv2/meta/resource_manager_test.go
@@ -67,7 +67,7 @@ func (suite *ResourceManagerSuite) TestManipulateResourceGroup() {
 
 	// test add duplicate rg
 	err = suite.manager.AddResourceGroup("rg1")
-	suite.NoError(err)
+	suite.Error(err)
 	// test delete rg
 	err = suite.manager.RemoveResourceGroup("rg1")
 	suite.NoError(err)