diff --git a/luser/routes.py b/luser/routes.py
index b980cab..a975f73 100644
--- a/luser/routes.py
+++ b/luser/routes.py
@@ -117,6 +117,10 @@ def register():
         if len(password) < 8:
             return 'Error: password is too short'
 
+        # Check if username has uppercase
+        if username.islower() == False:
+            return 'Error: uppercase characters in username are not allowed'
+
         # Create a LUSER connection
         luser = LUSER(LDAPHOST,LDAPADMINNAME,LDAPPASS,USERBASE,ALTUSERBASE)
         # Try to add user