diff --git a/pkg/appWorkflow/AppWorkflowService.go b/pkg/appWorkflow/AppWorkflowService.go
index b4ceedb2f7..cec9f6f96a 100644
--- a/pkg/appWorkflow/AppWorkflowService.go
+++ b/pkg/appWorkflow/AppWorkflowService.go
@@ -253,6 +253,7 @@ func (impl AppWorkflowServiceImpl) DeleteAppWorkflow(appWorkflowId int, userId i
 	}
 	if len(mappingForCI) > 0 {
 		return &util.ApiError{
+			Code:              "400",
 			InternalMessage:   "Workflow contains pipelines. First delete all pipelines in the workflow.",
 			UserDetailMessage: fmt.Sprintf("Workflow contains pipelines. First delete all pipelines in the workflow."),
 			UserMessage:       fmt.Sprintf("Workflow contains pipelines. First delete all pipelines in the workflow.")}
diff --git a/pkg/pipeline/CiHandler.go b/pkg/pipeline/CiHandler.go
index 19fdde0b2e..1326601d69 100644
--- a/pkg/pipeline/CiHandler.go
+++ b/pkg/pipeline/CiHandler.go
@@ -588,7 +588,11 @@ func (impl *CiHandlerImpl) CancelBuild(workflowId int) (int, error) {
 	}
 	if !(string(v1alpha1.NodePending) == workflow.Status || string(v1alpha1.NodeRunning) == workflow.Status) {
 		impl.Logger.Warn("cannot cancel build, build not in progress")
-		return 0, errors.New("cannot cancel build, build not in progress")
+		return 0, &util.ApiError{
+			Code:            "400",
+			UserMessage:     "cannot cancel build, build not in progress",
+			InternalMessage: "cannot cancel build, build not in progress",
+		}
 	}
 	isExt := workflow.Namespace != DefaultCiWorkflowNamespace
 	var env *repository3.Environment