diff --git a/github/AuthenticatedUser.py b/github/AuthenticatedUser.py
index f1417f2b..27cef266 100644
--- a/github/AuthenticatedUser.py
+++ b/github/AuthenticatedUser.py
@@ -426,7 +426,7 @@ class AuthenticatedUser(github.GithubObject.CompletableGithubObject):
         if client_secret is not github.GithubObject.NotSet:
             post_parameters["client_secret"] = client_secret
         if onetime_password is not None:
-            request_header = {'x-github-otp': onetime_password}  # pragma no cover (Should be covered)
+            request_header = {'X-GitHub-OTP': onetime_password}  # pragma no cover (Should be covered)
         else:
             request_header = None
         headers, data = self._requester.requestJsonAndCheck(