diff --git a/index.js b/index.js
index c41a8aa..235bb9e 100644
--- a/index.js
+++ b/index.js
@@ -48,6 +48,9 @@ module.exports = function functionArguments (fn, max) {
   if (fnStr[0] !== '(' && arrow) {
     fnStr = 'function (' + fnStr.slice(0, arrow) + ')' + fnStr.slice(arrow)
   }
+  if (max > fnStr.length) {
+    max = fnStr.length
+  }
 
   var match = fnStr.slice(0, Number(max) || 100).match(/.*\(([^\)]*)\)/)
   return match ? require('arr-map')(match[1].split(','), function (param) {
diff --git a/test.js b/test.js
index 7f3ede9..8e77be2 100644
--- a/test.js
+++ b/test.js
@@ -49,3 +49,10 @@ test('should get array with arguments names from regular function', function ()
   test.deepEqual(fnArgs(function * named (a, b, c) {}), ['a', 'b', 'c'])
 })
 
+test('should fail if `max` is bigger than fn.toString().length', function (done) {
+  function fixture (a, b) {
+    return [a, b]
+  }
+  test.deepEqual(fnArgs(fixture, 5555), ['a', 'b'])
+  done()
+})