diff --git a/tests/run-tests b/tests/run-tests
index 7df9563137..b275be0064 100755
--- a/tests/run-tests
+++ b/tests/run-tests
@@ -135,6 +135,8 @@ def run_micropython(pyb, args, test_file):
                 if i_mupy >= len(lines_mupy):
                     break
             output_mupy = b''.join(lines_mupy)
+            if os.name == 'nt':
+                output_mupy = output_mupy.replace(b'\n', b'\r\n')
 
         else:
             # a standard test