diff --git a/endpoints/index.py b/endpoints/index.py
index 2c2ca6e0a..4ecceeb99 100644
--- a/endpoints/index.py
+++ b/endpoints/index.py
@@ -44,11 +44,22 @@ def generate_headers(f):
 @app.route('/v1/users/', methods=['POST'])
 def create_user():
   user_data = request.get_json()
-  new_user = model.create_user(user_data['username'], user_data['password'],
-                               user_data['email'])
-  code = model.create_confirm_email_code(new_user)
-  send_confirmation_email(new_user.username, new_user.email, code.code)
-  return make_response('Created', 201)
+  username = user_data['username']
+  password = user_data['password']
+
+  existing_user = model.get_user(username)
+  if existing_user:
+    verified = model.verify_user(username, password)
+    if verified:
+      return make_response('Verified', 201)
+    else:
+      abort(401)
+  else:
+    # New user case
+    new_user = model.create_user(username, password, user_data['email'])
+    code = model.create_confirm_email_code(new_user)
+    send_confirmation_email(new_user.username, new_user.email, code.code)
+    return make_response('Created', 201)
 
 
 @app.route('/v1/users', methods=['GET'])