diff --git a/PCbuild/pythoncore.dsp b/PCbuild/pythoncore.dsp
index 5a84506..adcb706 100644
--- a/PCbuild/pythoncore.dsp
+++ b/PCbuild/pythoncore.dsp
@@ -323,6 +323,10 @@
 # End Source File
 # Begin Source File
 
+SOURCE=..\Modules\itertoolsmodule.c
+# End Source File
+# Begin Source File
+
 SOURCE=..\Parser\listnode.c
 # End Source File
 # Begin Source File