diff --git a/tester.py b/tester.py
index 0bc0c6cdb2dae5ed905d888fc456cf542a0e7669..9fa611ab08f2d1e703d3db45c3a7214f81fb9384 100755
--- a/tester.py
+++ b/tester.py
@@ -165,7 +165,7 @@ class Tester():
         # Get MS instances
         ms_users = list()
         for user in os.listdir('/home'):
-            if os.path.exists('/home/%s/msinstance' % user) and user == msuser:
+            if os.path.exists('/home/%s/msinstance' % user) and (not msuser or user == msuser):
                 ms_users.append(user)
         # Get MediaServer tests
         if ms_users: