diff --git a/BaseTools/Source/Python/Ecc/c.py b/BaseTools/Source/Python/Ecc/c.py
index d7b9598438..35b7405e55 100644
--- a/BaseTools/Source/Python/Ecc/c.py
+++ b/BaseTools/Source/Python/Ecc/c.py
@@ -1,7 +1,7 @@
 ## @file
 # This file is used to be the c coding style checking of ECC tool
 #
-# Copyright (c) 2009 - 2016, Intel Corporation. All rights reserved.<BR>
+# Copyright (c) 2009 - 2017, Intel Corporation. All rights reserved.<BR>
 # This program and the accompanying materials
 # are licensed and made available under the terms and conditions of the BSD License
 # which accompanies this distribution.  The full text of the license may be found at
@@ -271,7 +271,7 @@ def GetIdentifierList():
 def StripNonAlnumChars(Str):
     StrippedStr = ''
     for Char in Str:
-        if Char.isalnum():
+        if Char.isalnum() or Char == '_':
             StrippedStr += Char
     return StrippedStr