diff --git a/clang-tools-extra/test/clang-tidy/check_clang_tidy.py b/clang-tools-extra/test/clang-tidy/check_clang_tidy.py
--- a/clang-tools-extra/test/clang-tidy/check_clang_tidy.py
+++ b/clang-tools-extra/test/clang-tidy/check_clang_tidy.py
@@ -159,7 +159,7 @@
     diff_output = e.output
 
   print('------------------------------ Fixes -----------------------------\n' +
-        diff_output.decode() +
+        diff_output.decode(errors='ignore') +
         '\n------------------------------------------------------------------')
 
   if has_check_fixes: