diff --git a/lldb/test/API/lldbtest.py b/lldb/test/API/lldbtest.py
--- a/lldb/test/API/lldbtest.py
+++ b/lldb/test/API/lldbtest.py
@@ -120,8 +120,8 @@
 
         if sys.version_info.major == 2:
             # In Python 2, string objects can contain Unicode characters.
-            out = out.decode('utf-8')
-            err = err.decode('utf-8')
+            out = out.decode('utf-8', 'replace')
+            err = err.decode('utf-8', 'replace')
 
         output = """Script:\n--\n%s\n--\nExit Code: %d\n""" % (
             ' '.join(cmd), exitCode)