diff --git a/package.json b/package.json
index 60946ff6..11241671 100644
--- a/package.json
+++ b/package.json
@@ -63,7 +63,7 @@
     "minimatch": "^3.0.4",
     "mkdirp": "^0.5.1",
     "pre-commit": "^1.2.2",
-    "proxyquire": "^2.0.1",
+    "proxyquire": "^2.1.3",
     "rimraf": "^3.0.0",
     "simple-get": "^3.0.3",
     "sinon": "^7.3.2",
diff --git a/test/start.test.js b/test/start.test.js
index 46cd95ef..60f95d5b 100644
--- a/test/start.test.js
+++ b/test/start.test.js
@@ -483,6 +483,53 @@ test('crash on unhandled rejection', t => {
   })
 })
 
+if (!process.version.match(/v[0-6]\..*/g)) {
+  test('should start the server with inspect options and the defalut port is 9320', t => {
+    t.plan(4)
+
+    const start = proxyquire('../start', {
+      inspector: {
+        open (p) {
+          t.strictEqual(p, 9320)
+          t.pass('inspect open called')
+        }
+      }
+    })
+    const argv = ['--d', './examples/plugin.js']
+
+    start.start(argv, (err, fastify) => {
+      t.error(err)
+
+      fastify.close(() => {
+        t.pass('server closed')
+      })
+    })
+  })
+
+  test('should start the server with inspect options and use the exactly port', t => {
+    t.plan(4)
+
+    const port = getPort()
+    const start = proxyquire('../start', {
+      inspector: {
+        open (p) {
+          t.strictEqual(p, Number(port))
+          t.pass('inspect open called')
+        }
+      }
+    })
+    const argv = ['--d', '--debug-port', port, './examples/plugin.js']
+
+    start.start(argv, (err, fastify) => {
+      t.error(err)
+
+      fastify.close(() => {
+        t.pass('server closed')
+      })
+    })
+  })
+}
+
 test('boolean env are not overridden if no arguments are passed', t => {
   t.plan(1)