diff --git a/bsp/lpc43xx/M0/SConstruct b/bsp/lpc43xx/M0/SConstruct
index 3a52eb9a43..145b29d70f 100644
--- a/bsp/lpc43xx/M0/SConstruct
+++ b/bsp/lpc43xx/M0/SConstruct
@@ -35,12 +35,12 @@ if rtconfig.CROSS_TOOL == 'gcc':
 
     if sys.platform.startswith('linux'):
         import glob
-        ocwd = os.getcwdu()
+        ocwd = os.getcwd()
         res = os.system('cd ../Libraries/; find -name \*.o -exec rm {} \;')
         os.chdir(ocwd)
     else:
         # Assume Windows.
-        ocwd = os.getcwdu()
+        ocwd = os.getcwd()
         print('TODO: remove the object files in ../Libraries')
         os.chdir(ocwd)
 
diff --git a/tools/mkromfs.py b/tools/mkromfs.py
index 5371106987..120053be40 100644
--- a/tools/mkromfs.py
+++ b/tools/mkromfs.py
@@ -85,7 +85,7 @@ class Folder(object):
         # TODO: take care of the unicode names
         for ent in os.listdir(u'.'):
             if os.path.isdir(ent):
-                cwd = os.getcwdu()
+                cwd = os.getcwd()
                 d = Folder(ent)
                 # depth-first
                 os.chdir(os.path.join(cwd, ent))