diff --git a/src/system.js b/src/system.js
index ca83f8f92..2bb6dc493 100644
--- a/src/system.js
+++ b/src/system.js
@@ -26,8 +26,11 @@ const apps = require('./apps.js'),
 
 const DU_CMD = path.join(__dirname, 'scripts/du.sh');
 
-async function du(file) {
-    const [error, stdoutResult] = await safe(shell.promises.sudo('system', [ DU_CMD, file ], {}));
+async function du(file, options) {
+    assert.strictEqual(typeof file, 'string');
+    assert.strictEqual(typeof options, 'object');
+
+    const [error, stdoutResult] = await safe(shell.promises.sudo('system', [ DU_CMD, file, options.exclude || '' ], {}));
     if (error) throw new BoxError(BoxError.FS_ERROR, error);
 
     return parseInt(stdoutResult.trim(), 10);
diff --git a/src/test/docker-test.js b/src/test/docker-test.js
index 5aadc593e..2868a6b75 100644
--- a/src/test/docker-test.js
+++ b/src/test/docker-test.js
@@ -19,6 +19,5 @@ describe('docker', function () {
     it('can df', async function () {
         const output = await docker.df();
         expect(output).to.be.ok();
-        console.log(output);
     });
 });
diff --git a/src/test/system-test.js b/src/test/system-test.js
index 7f6515dff..c7702a2f3 100644
--- a/src/test/system-test.js
+++ b/src/test/system-test.js
@@ -38,7 +38,7 @@ describe('System', function () {
     });
 
     it('can get du', async function () {
-        const usage = await system.du(__dirname);
+        const usage = await system.du(__dirname, {});
         expect(usage).to.be.a('number');
         console.log(usage);
     });