diff --git a/nsis.py b/nsis.py
index 86f43c89..ce2b7d72 100644
--- a/nsis.py
+++ b/nsis.py
@@ -265,6 +265,7 @@ def create(self, pathname="base.nsi"):
             'unregister_com_servers_dll': ''.join([unregister_com_server_dll % comserver for comserver in self.comserver_files_dll]),
             'unregister_com_servers_exe': ''.join([unregister_com_server_tlb % comserver for comserver in self.comserver_files_tlb]),
         })
+        ofi.close()
 
     def compile(self, pathname="base.nsi"):
         os.startfile(pathname, 'compile')