diff --git a/lib/authenticator.js b/lib/authenticator.js
index d374eb2f..913df9a9 100644
--- a/lib/authenticator.js
+++ b/lib/authenticator.js
@@ -243,11 +243,10 @@ Authenticator.prototype.session = function session(options) {
  * @api public
  */
 
-Authenticator.prototype.sessionManager = function(mgr) {
+Authenticator.prototype.sessionManager = function sessionManager(mgr) {
   this._sm = mgr;
   return this;
-}
-
+};
 
 /**
  * Registers a function used to serialize user objects into the session.
diff --git a/test/authenticator.test.js b/test/authenticator.test.js
index 1dd229ba..49f43ee0 100644
--- a/test/authenticator.test.js
+++ b/test/authenticator.test.js
@@ -7,6 +7,17 @@ const Authenticator = require('../lib/authenticator');
 
 
 describe('Authenticator', () => {
+
+  describe('#sessionManager', () => {
+    it('should set custom session manager', () => {
+      const passport = new Authenticator();
+      const sessionManager = {};
+      passport.sessionManager(sessionManager);
+
+      expect(passport._sm).to.equal(sessionManager);
+    });
+  });
+
   describe('#use', () => {
     describe('with instance name', () => {
       function Strategy() {