diff --git a/index.d.ts b/index.d.ts
index c6bc2f6..e776902 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -80,7 +80,7 @@ declare namespace LightMyRequest {
     trailers: { [key: string]: string }
     payload: string
     body: string
-    json: () => any
+    json: <T = any>() => T
     cookies: Array<object>
   }
 
diff --git a/test/index.test-d.ts b/test/index.test-d.ts
index 262b1aa..42b79e6 100644
--- a/test/index.test-d.ts
+++ b/test/index.test-d.ts
@@ -77,3 +77,6 @@ type ParsedValue = { field: string }
 const response: Response = await inject(dispatch)
 const parsedValue: ParsedValue = response.json()
 expectType<ParsedValue>(parsedValue)
+
+const parsedValueUsingGeneric = response.json<ParsedValue>()
+expectType<ParsedValue>(parsedValueUsingGeneric)