diff --git a/package.json b/package.json
index 687c33df..49a51a8b 100644
--- a/package.json
+++ b/package.json
@@ -59,7 +59,8 @@
     "mocha": "^2.2.5",
     "mocha-jshint": "^2.2.3",
     "node-cpplint": "^0.4.0",
-    "rimraf": "^2.4.2"
+    "rimraf": "^2.4.2",
+    "bufferutil": "^1.2.1"
   },
   "license": "Apache-2.0",
   "engines": {
diff --git a/test/unit/gamma.js b/test/unit/gamma.js
index b109e28e..5cf36d52 100755
--- a/test/unit/gamma.js
+++ b/test/unit/gamma.js
@@ -16,7 +16,7 @@ describe('Gamma correction', function() {
         assert.strictEqual('jpeg', info.format);
         assert.strictEqual(129, info.width);
         assert.strictEqual(111, info.height);
-        fixtures.assertSimilar(fixtures.expected('gamma-0.0.jpg'), data, done);
+        fixtures.assertSimilar(fixtures.expected('gamma-0.0.jpg'), data, {threshold: 12}, done);
       });
   });
 
diff --git a/test/unit/require.js b/test/unit/require.js
new file mode 100644
index 00000000..e195e5a1
--- /dev/null
+++ b/test/unit/require.js
@@ -0,0 +1,15 @@
+'use strict';
+
+describe('Require-time checks', function() {
+
+  /*
+    Including sharp alongside another C++ module that does not require
+    -stdlib=libc++ (for its C++11 features) has caused clang/llvm to
+    segfault due to the use of static function variables.
+  */
+  it('Require alongside C++ module that does not use libc++', function() {
+    var bufferutil = require('bufferutil');
+    var sharp = require('../../index');
+  });
+
+});