diff --git a/app/cli.py b/app/cli.py
index 00c87bf6..09ff05f5 100644
--- a/app/cli.py
+++ b/app/cli.py
@@ -148,8 +148,8 @@ def register(app):
             user_name = input("Admin user name (ideally not 'admin'): ")
             email = input("Admin email address: ")
             password = input("Admin password: ")
-            while '@' in user_name:
-                print('User name cannot be an email address.')
+            while '@' in user_name or ' ' in user_name:
+                print('User name cannot be an email address or have spaces.')
                 user_name = input("Admin user name (ideally not 'admin'): ")
             verification_token = random_token(16)
             private_key, public_key = RsaKeys.generate_keypair()