diff --git a/oioioi/programs/handlers.py b/oioioi/programs/handlers.py
index a28cb207f..4f29a528b 100755
--- a/oioioi/programs/handlers.py
+++ b/oioioi/programs/handlers.py
@@ -695,9 +695,9 @@ def add_result_percentage(env, **kwargs):
         return env
 
     for test_name, test_result in env['test_results'].items():
-        if (test_result['result_percentage'] == 100
-                or test_result['result_percentage'] == 0):
+        percentage = test_result.get('result_percentage', 0)
+        if percentage == 100 or percentage == 0:
             continue
-        test_result['result_string'] = _("Granted %d%% points, comment") % test_result['result_percentage'] + \
+        test_result['result_string'] = _("Granted %d%% points, comment") % percentage + \
                                        ': ' + test_result['result_string']
     return env