diff --git a/src/index.ts b/src/index.ts
index cb13b8d..6d9ffa0 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -35,7 +35,7 @@ const rewriteResRaw = (res: Response) => {
     if (isJsonContent && body instanceof Buffer) {
       try {
         const bodyJson = JSON.parse(body.toString('utf8'));
-        if (bodyJson.data) {
+        if (bodyJson && bodyJson.data) {
           const newResponseData = rewriteHandler.rewriteResponse(bodyJson.data);
           const newResBodyJson = { ...bodyJson, data: newResponseData };
           // assume this was pretty-printed if we're here and not in the res.json handler
diff --git a/test/index.test.ts b/test/index.test.ts
index 66a8969..b724e3a 100644
--- a/test/index.test.ts
+++ b/test/index.test.ts
@@ -363,7 +363,7 @@ describe('middleware test', () => {
     expect(invalidQueryRes.body.data).toEqual({ random: true });
   });
 
-  it('ignores invalid json responses', async () => {
+  it('ignores invalid json responses sent via response.json()', async () => {
     const app = express();
 
     app.use(
@@ -402,6 +402,60 @@ describe('middleware test', () => {
     expect(invalidQueryRes.body).toEqual('jimmy');
   });
 
+  it('ignores invalid json responses sent via response.end()', async () => {
+    const app = express();
+
+    app.use(
+      '/graphql',
+      graphqlRewriterMiddleware({
+        rewriters: [
+          new FieldArgsToInputTypeRewriter({
+            fieldName: 'makePokemon',
+            argNames: ['name']
+          }),
+          new NestFieldOutputsRewriter({
+            fieldName: 'makePokemon',
+            newOutputName: 'pokemon',
+            outputsToNest: ['id', 'name']
+          })
+        ]
+      })
+    );
+
+    app.use('/graphql', (req, res) => {
+      const messedUpRes = Buffer.from('jisdhfiods{{{{', 'utf8');
+      res.setHeader('Content-Type', 'application/json; charset=utf-8');
+      res.setHeader('Content-Length', String(messedUpRes.length));
+      res.end(messedUpRes);
+    });
+
+    const deprecatedQuery = `
+      mutation {
+        makePokemon(name: "Squirtle") {
+          id
+          name
+        }
+      }
+    `;
+
+    const invalidQueryRes = await request(app)
+      .post('/graphql')
+      .send({ query: deprecatedQuery })
+      // disable supertest json parsing
+      .buffer(true)
+      .parse((res, cb) => {
+        let data = Buffer.from('');
+        res.on('data', chunk => {
+          data = Buffer.concat([data, chunk]);
+        });
+        res.on('end', () => {
+          cb(null, data.toString());
+        });
+      });
+
+    expect(invalidQueryRes.body).toEqual('jisdhfiods{{{{');
+  });
+
   it('is able to rewriter responses with pretty printing enabled on express-graphql', async () => {
     const app = setupMutationApp({ pretty: true });
     // in the past, we didn't use input or output types correctly