diff --git a/Mac/Lib/mkcwproject/__init__.py b/Mac/Lib/mkcwproject/__init__.py
index 6551b223f91..a9e05629ca0 100644
--- a/Mac/Lib/mkcwproject/__init__.py
+++ b/Mac/Lib/mkcwproject/__init__.py
@@ -56,6 +56,7 @@ def buildproject(projectfile):
 	prjfss = macfs.FSSpec(projectfile)
 	cw.open(prjfss)
 	cw.Make_Project()	# XXX Should set target
+	cw.Close_Project()
 	
 def cleanproject(projectfile):
 	cw = cwtalker.MyCodeWarrior(start=1)