diff --git a/kallithea/model/db.py b/kallithea/model/db.py
--- a/kallithea/model/db.py
+++ b/kallithea/model/db.py
@@ -421,6 +421,7 @@ class User(Base, BaseModel):
     user_perms = relationship('UserToPerm', primaryjoin="User.user_id==UserToPerm.user_id", cascade='all')
 
     repositories = relationship('Repository')
+    repo_groups = relationship('RepoGroup')
     user_followers = relationship('UserFollowing', primaryjoin='UserFollowing.follows_user_id==User.user_id', cascade='all')
     followings = relationship('UserFollowing', primaryjoin='UserFollowing.user_id==User.user_id', cascade='all')
 
diff --git a/kallithea/model/user.py b/kallithea/model/user.py
--- a/kallithea/model/user.py
+++ b/kallithea/model/user.py
@@ -258,10 +258,17 @@ class UserModel(BaseModel):
         if user.repositories:
             repos = [x.repo_name for x in user.repositories]
             raise UserOwnsReposException(
-                _(u'user "%s" still owns %s repositories and cannot be '
-                  'removed. Switch owners or remove those repositories. %s')
+                _(u'User "%s" still owns %s repositories and cannot be '
+                  'removed. Switch owners or remove those repositories: %s')
                 % (user.username, len(repos), ', '.join(repos))
             )
+        if user.repo_groups:
+            repogroups = [x.group_name for x in user.repo_groups]
+            raise UserOwnsReposException(
+                _(u'User "%s" still owns %s repository groups and cannot be '
+                  'removed. Switch owners or remove those repository groups: %s')
+                % (user.username, len(repogroups), ', '.join(repogroups))
+            )
         self.sa.delete(user)
 
         from kallithea.lib.hooks import log_delete_user