diff --git a/openslides/participant/api.py b/openslides/participant/api.py
index 05b5c8bf4..3e5856391 100644
--- a/openslides/participant/api.py
+++ b/openslides/participant/api.py
@@ -47,7 +47,7 @@ def gen_username(first_name, last_name):
     i = 0
     while True:
         i += 1
-        testname = "%s%s%s" % (first_name, last_name, i)
+        testname = "%s %s %s" % (first_name, last_name, i)
         try:
             User.objects.get(username=testname)
         except User.DoesNotExist: