diff --git a/lib/assert.js b/lib/assert.js
index 70eda84ff7..4f6c46c9a7 100644
--- a/lib/assert.js
+++ b/lib/assert.js
@@ -47,6 +47,7 @@ assert.AssertionError = function AssertionError (options) {
     Error.captureStackTrace(this, stackStartFunction);
   }
 };
+process.inherits(assert.AssertionError, Error);
 
 assert.AssertionError.prototype.toString = function() {
   if (this.message) {