2 files changed, 18 insertions, 6 deletions
diff --git a/cli/js/lib.deno.ns.d.ts b/cli/js/lib.deno.ns.d.ts
index f9438ed9c..f3ee04243 100644
--- a/cli/js/lib.deno.ns.d.ts
+++ b/cli/js/lib.deno.ns.d.ts
@@ -1779,9 +1779,15 @@ declare namespace Deno {
   export class Process<T extends RunOptions = RunOptions> {
     readonly rid: number;
     readonly pid: number;
-    readonly stdin: T["stdin"] extends "piped" ? Writer & Closer : null;
-    readonly stdout: T["stdout"] extends "piped" ? Reader & Closer : null;
-    readonly stderr: T["stderr"] extends "piped" ? Reader & Closer : null;
+    readonly stdin: T["stdin"] extends "piped"
+      ? Writer & Closer
+      : (Writer & Closer) | null;
+    readonly stdout: T["stdout"] extends "piped"
+      ? Reader & Closer
+      : (Writer & Closer) | null;
+    readonly stderr: T["stderr"] extends "piped"
+      ? Reader & Closer
+      : (Writer & Closer) | null;
     /** Resolves to the current status of the process. */
     status(): Promise<ProcessStatus>;
     /** Buffer the stdout until EOF and return it as `Uint8Array`.
diff --git a/cli/js/process.ts b/cli/js/process.ts
index f318b0c1c..c7c3358f5 100644
--- a/cli/js/process.ts
+++ b/cli/js/process.ts
@@ -32,9 +32,15 @@ async function runStatus(rid: number): Promise<ProcessStatus> {
 export class Process<T extends RunOptions = RunOptions> {
   readonly rid: number;
   readonly pid: number;
-  readonly stdin!: T["stdin"] extends "piped" ? Writer & Closer : null;
-  readonly stdout!: T["stdout"] extends "piped" ? Reader & Closer : null;
-  readonly stderr!: T["stderr"] extends "piped" ? Reader & Closer : null;
+  readonly stdin!: T["stdin"] extends "piped"
+    ? Writer & Closer
+    : (Writer & Closer) | null;
+  readonly stdout!: T["stdout"] extends "piped"
+    ? Reader & Closer
+    : (Writer & Closer) | null;
+  readonly stderr!: T["stderr"] extends "piped"
+    ? Reader & Closer
+    : (Writer & Closer) | null;
 
   // @internal
   constructor(res: RunResponse) {