diff --git a/BaseTools/Source/Python/Common/Misc.py b/BaseTools/Source/Python/Common/Misc.py
index 565a5ad40b..c7daf5417c 100644
--- a/BaseTools/Source/Python/Common/Misc.py
+++ b/BaseTools/Source/Python/Common/Misc.py
@@ -1032,6 +1032,7 @@ def ParseFieldValue (Value):
             p.stderr.close()
         if err:
             raise BadExpression("DevicePath: %s" % str(err))
+        out = out.decode()
         Size = len(out.split())
         out = ','.join(out.split())
         return '{' + out + '}', Size