diff --git a/types/koa-joi-router/index.d.ts b/types/koa-joi-router/index.d.ts
index 54cf148240..8ee1563370 100644
--- a/types/koa-joi-router/index.d.ts
+++ b/types/koa-joi-router/index.d.ts
@@ -31,6 +31,8 @@ declare namespace createRouter {
 
     type Method = (path: string|RegExp, handlerOrConfig: Handler | object, ...handlers: Handler[]) => Router;
 
+    type OutputValidation = { body: Joi.SchemaLike } | { headers: Joi.SchemaLike };
+
     interface Spec {
         method: string|string[];
         path: string|RegExp;
@@ -47,7 +49,7 @@ declare namespace createRouter {
             formOptions?: CoBody.Options;
             jsonOptions?: CoBody.Options;
             multipartOptions?: CoBody.Options;
-            output?: {[status: string]: Joi.SchemaLike};
+            output?: {[status: string]: OutputValidation};
             continueOnError?: boolean;
         };
         meta?: any;
diff --git a/types/koa-joi-router/koa-joi-router-tests.ts b/types/koa-joi-router/koa-joi-router-tests.ts
index 160c3834c1..050ad4d5a1 100644
--- a/types/koa-joi-router/koa-joi-router-tests.ts
+++ b/types/koa-joi-router/koa-joi-router-tests.ts
@@ -41,8 +41,16 @@ const spec4: router.Spec = {
   validate: {
     type: 'json',
     output: {
-      201: Joi.object(),
-      '400,404': Joi.object(),
+      201: {
+        body: Joi.object(),
+      },
+      '400,404': {
+        headers: Joi.object(),
+        body: Joi.object(),
+      },
+      '500-599': {
+        headers: Joi.object(),
+      },
     },
     jsonOptions: {
         limit: '10kb'