diff --git a/src/core.ts b/src/core.ts
index 7e7f463443..908ac4c015 100644
--- a/src/core.ts
+++ b/src/core.ts
@@ -43,7 +43,7 @@ export type Shell = (
 
 const processCwd = Symbol('processCwd')
 
-export type Options = {
+export interface Options {
   [processCwd]: string
   cwd?: string
   verbose: boolean