diff --git a/src/context.ts b/src/context.ts
index ac87e0d4c6..75fcb6f30d 100644
--- a/src/context.ts
+++ b/src/context.ts
@@ -13,6 +13,7 @@
 // limitations under the License.
 
 import { AsyncLocalStorage } from 'node:async_hooks'
+import { spawn } from 'node:child_process'
 
 export type Options = {
   verbose: boolean | number
@@ -22,6 +23,7 @@ export type Options = {
   shell: string
   maxBuffer: number
   quote: (v: string) => string
+  spawn: typeof spawn
   logOutput?: 'stdout' | 'stderr'
   logFormat?: (...msg: any[]) => string | string[]
   logPrint?: (data: any, err?: any) => void
diff --git a/src/core.ts b/src/core.ts
index c18bbdff33..9ce7770e49 100644
--- a/src/core.ts
+++ b/src/core.ts
@@ -23,7 +23,7 @@ import { inspect, promisify } from 'node:util'
 import { spawn } from 'node:child_process'
 
 import { chalk, which } from './goods.js'
-import { runInCtx, getCtx, setRootCtx, Context } from './context.js'
+import { runInCtx, getCtx, setRootCtx, Context, Options } from './context.js'
 import { printCmd, log } from './print.js'
 import { quote, substitute } from './guards.js'
 
@@ -31,7 +31,11 @@ import psTreeModule from 'ps-tree'
 
 const psTree = promisify(psTreeModule)
 
-export function $(pieces: TemplateStringsArray, ...args: any[]) {
+interface Zx extends Options {
+  (pieces: TemplateStringsArray, ...args: any[]): ProcessPromise
+}
+
+export const $: Zx = function (pieces: TemplateStringsArray, ...args: any[]) {
   let resolve, reject
   let promise = new ProcessPromise((...args) => ([resolve, reject] = args))