diff --git a/node/node.d.ts b/node/node.d.ts
index 0ca514e9e8..3a260b0530 100644
--- a/node/node.d.ts
+++ b/node/node.d.ts
@@ -98,7 +98,7 @@ declare module NodeJS {
 
     export interface ReadableStream extends EventEmitter {
         readable: boolean;
-        read(size?: number): any;
+        read(size?: number): string|Buffer;
         setEncoding(encoding: string): void;
         pause(): void;
         resume(): void;