diff --git a/package.json b/package.json
index a675423..6a1897e 100644
--- a/package.json
+++ b/package.json
@@ -47,6 +47,6 @@
     "mocha": "~2.5.3",
     "sinon": "~1.17.4",
     "sinon-chai": "~2.8.0",
-    "supertest": "~1.2.0"
+    "supertest": "~2.0.0"
   }
 }
diff --git a/test/test.js b/test/test.js
index a307086..cf2f345 100644
--- a/test/test.js
+++ b/test/test.js
@@ -122,7 +122,7 @@ describe('`res.sendSeekable`', function () {
       });
 
       it('sets the `Content-Length` header to the content byte length', function (done) {
-        appTester.expect('Content-Length', content.length, done);
+        appTester.expect('Content-Length', content.length.toString(), done);
       });
 
       testInvariantBehavior();
@@ -146,7 +146,7 @@ describe('`res.sendSeekable`', function () {
         });
 
         it('sets the `Content-Length` header to the content byte length', function (done) {
-          appTester.expect('Content-Length', content.length, done);
+          appTester.expect('Content-Length', content.length.toString(), done);
         });
 
         it('sets the `Content-Type` header if configured', function (done) {