diff --git a/lib/_debug_agent.js b/lib/_debug_agent.js
index 63c5035789..152a7c65a6 100644
--- a/lib/_debug_agent.js
+++ b/lib/_debug_agent.js
@@ -48,6 +48,7 @@ function Agent() {
 
   this.first = true;
   this.binding = process._debugAPI;
+  assert(this.binding, 'Debugger agent running without bindings!');
 
   var self = this;
   this.binding.onmessage = function(msg) {
@@ -57,7 +58,6 @@ function Agent() {
   };
 
   this.clients = [];
-  assert(this.binding, 'Debugger agent running without bindings!');
 }
 util.inherits(Agent, net.Server);
 
diff --git a/test/parallel/test-debug-agent.js b/test/parallel/test-debug-agent.js
new file mode 100644
index 0000000000..0bb5d7f9be
--- /dev/null
+++ b/test/parallel/test-debug-agent.js
@@ -0,0 +1,6 @@
+'use strict';
+require('../common');
+const assert = require('assert');
+
+assert.throws(() => { require('_debug_agent').start(); },
+  assert.AssertionError);