diff --git a/winver.py b/winver.py
index e239690..47cda21 100644
--- a/winver.py
+++ b/winver.py
@@ -26,6 +26,7 @@ def getWindowsVersion(path):
         version = ""
         pe = pefile.PE(getWindowsDirectory(path) + "/System32/ntdll.dll")
         version = str(pe.FileInfo[0].StringTable[0].entries[b'ProductVersion'],'utf-8')
+	pe.close()
         if re.match("(3|4)\.",version) != None:
             return _WIN_NT
         elif re.match("5\.0", version) != None: