diff --git a/PCbuild/readme.txt b/PCbuild/readme.txt
index 67fe894..07f9b2a 100644
--- a/PCbuild/readme.txt
+++ b/PCbuild/readme.txt
@@ -39,6 +39,8 @@
     .exe
 pythonw
     pythonw.exe, a variant of python.exe that doesn't pop up a DOS box
+_csv
+    C support for the comma-separated values module
 _socket
     socketmodule.c
 _sre