diff --git a/lib/handlers/authenticate-handler.js b/lib/handlers/authenticate-handler.js
index dc9117b27..327eadbb8 100644
--- a/lib/handlers/authenticate-handler.js
+++ b/lib/handlers/authenticate-handler.js
@@ -216,15 +216,25 @@ AuthenticateHandler.prototype.getAccessToken = function(token) {
  */
 
 AuthenticateHandler.prototype.validateAccessToken = function(accessToken) {
-  if (!(accessToken.accessTokenExpiresAt instanceof Date)) {
-    throw new ServerError('Server error: `accessTokenExpiresAt` must be a Date instance');
+  if (this.model.validateAccessToken) {
+    return promisify(this.model.validateAccessToken, 1).call(this.model, accessToken)
+      .then(function (isValid) {
+        if (!isValid) {
+          throw new InvalidTokenError('Invalid token: access token has expired');
+        }
+        return accessToken;
+      });
+  } else {
+    if (!(accessToken.accessTokenExpiresAt instanceof Date)) {
+      throw new ServerError('Server error: `accessTokenExpiresAt` must be a Date instance');
+    }
+
+    if (accessToken.accessTokenExpiresAt < new Date()) {
+      throw new InvalidTokenError('Invalid token: access token has expired');
+    }
+
+    return accessToken;
   }
-
-  if (accessToken.accessTokenExpiresAt < new Date()) {
-    throw new InvalidTokenError('Invalid token: access token has expired');
-  }
-
-  return accessToken;
 };
 
 /**