diff --git a/management/univention-management-console-module-top/umc/python/top/__init__.py b/management/univention-management-console-module-top/umc/python/top/__init__.py
index d8b09e7..c62577f 100644
--- a/management/univention-management-console-module-top/umc/python/top/__init__.py
+++ b/management/univention-management-console-module-top/umc/python/top/__init__.py
@@ -66,7 +66,7 @@ def query(self, request):
 			listEntry['pid'] = process.pid
 			listEntry['cpu'] = 0.0
 			listEntry['mem'] = process.get_memory_percent()
-			listEntry['command'] = ' '.join(process.cmdline)
+			listEntry['command'] = ' '.join(process.cmdline or [])
 			if listEntry['command'] == '':
 				listEntry['command'] = process.name
 			if category == 'all':