diff --git a/bin/tools/yaml_import.py b/bin/tools/yaml_import.py
index 2b5c982ca7b..6e5977d8e6a 100644
--- a/bin/tools/yaml_import.py
+++ b/bin/tools/yaml_import.py
@@ -106,7 +106,7 @@ class TestReport(object):
             success += self._report[severity][True]
             failure += self._report[severity][False]
         res.append("total\t%s\t%s" % (success, failure))
-        res.append("end of report (%s assertion(s) checked)" % success + failure)
+        res.append("end of report (%s assertion(s) checked)" % (success + failure))
         return "\n".join(res)
 
 class RecordDictWrapper(dict):