diff --git a/internal/test/smoke/domain_update_system_test.go b/internal/test/smoke/domain_update_system_test.go
index 2f29e8c6..817864a3 100644
--- a/internal/test/smoke/domain_update_system_test.go
+++ b/internal/test/smoke/domain_update_system_test.go
@@ -102,8 +102,12 @@ func (s *SuiteDomainUpdateAgent) TestUpdateDomain() {
 			},
 			Expected: TestCaseExpect{
 				StatusCode: http.StatusBadRequest,
-				BodyFunc: WrapBodyFuncErrorResponse(func(t *testing.T, body *ErrorResponse) error {
-					assert.Equal(t, "'domain_name' may not be changed", body.Message)
+				BodyFunc: WrapBodyFuncErrorResponse(func(t *testing.T, body *public.ErrorResponse) error {
+					assert.Equal(t, builder_api.NewErrorResponse().
+						Add(*builder_api.NewErrorInfo(http.StatusBadRequest).
+							WithTitle("'domain_name' may not be changed").
+							Build()).
+						Build(), body)
 					return nil
 				}),
 			},
@@ -119,8 +123,12 @@ func (s *SuiteDomainUpdateAgent) TestUpdateDomain() {
 			},
 			Expected: TestCaseExpect{
 				StatusCode: http.StatusBadRequest,
-				BodyFunc: WrapBodyFuncErrorResponse(func(t *testing.T, body *ErrorResponse) error {
-					assert.Equal(t, "'realm_name' may not be changed", body.Message)
+				BodyFunc: WrapBodyFuncErrorResponse(func(t *testing.T, body *public.ErrorResponse) error {
+					assert.Equal(t, builder_api.NewErrorResponse().
+						Add(*builder_api.NewErrorInfo(http.StatusBadRequest).
+							WithTitle("'realm_name' may not be changed").
+							Build()).
+						Build(), body)
 					return nil
 				}),
 			},
diff --git a/internal/test/smoke/suite_base_test.go b/internal/test/smoke/suite_base_test.go
index 784f43fb..f496c99a 100644
--- a/internal/test/smoke/suite_base_test.go
+++ b/internal/test/smoke/suite_base_test.go
@@ -870,16 +870,7 @@ func TestSuite(t *testing.T) {
 	suite.Run(t, new(SuiteSystemEndpoints))
 }
 
-// ErrorResponse represents the error response from the API
-//
-// Note: the structure is different than the public.ErrorResponse
-// as the API doesn't actually return a public.ErrorResponse which it should.
-type ErrorResponse struct {
-	Error   string `json:"error"`
-	Message string `json:"message"`
-}
-
-type BodyFuncErrorResponse func(t *testing.T, body *ErrorResponse) error
+type BodyFuncErrorResponse func(t *testing.T, body *public.ErrorResponse) error
 
 func WrapBodyFuncErrorResponse(predicate BodyFuncErrorResponse) BodyFunc {
 	if predicate == nil {
@@ -888,7 +879,7 @@ func WrapBodyFuncErrorResponse(predicate BodyFuncErrorResponse) BodyFunc {
 		}
 	}
 	return func(t *testing.T, body []byte) bool {
-		var data ErrorResponse
+		var data public.ErrorResponse
 		if err := json.Unmarshal(body, &data); err != nil {
 			require.Fail(t, fmt.Errorf("Error unmarshalling body: %w", err).Error())
 			return false