diff --git a/x-pack/legacy/plugins/siem/public/containers/case/api.ts b/x-pack/legacy/plugins/siem/public/containers/case/api.ts
index 5e1a6f6812a4f..12b4c80a2dd89 100644
--- a/x-pack/legacy/plugins/siem/public/containers/case/api.ts
+++ b/x-pack/legacy/plugins/siem/public/containers/case/api.ts
@@ -204,7 +204,7 @@ export const patchComment = async (
   return convertToCamelCase<CaseResponse, Case>(decodeCaseResponse(response));
 };
 
-export const deleteCases = async (caseIds: string[], signal: AbortSignal): Promise<boolean> => {
+export const deleteCases = async (caseIds: string[], signal: AbortSignal): Promise<string> => {
   const response = await KibanaServices.get().http.fetch<string>(CASES_URL, {
     method: 'DELETE',
     query: { ids: JSON.stringify(caseIds) },