diff --git a/tools/run_tests/report_utils.py b/tools/run_tests/report_utils.py
index 0032a985232..df114e5dae1 100644
--- a/tools/run_tests/report_utils.py
+++ b/tools/run_tests/report_utils.py
@@ -47,7 +47,7 @@ def _filter_msg(msg, output_format):
     # that make XML report unparseable.
     filtered_msg = filter(
         lambda x: x in string.printable and x != '\f' and x != '\v',
-        msg.decode(errors='ignore'))
+        msg.decode('UTF-8', 'ignore'))
     if output_format == 'HTML':
       filtered_msg = filtered_msg.replace('"', '"')
     return filtered_msg