diff --git a/tab2opf.py b/tab2opf.py
index 20064b6..919b3a7 100755
--- a/tab2opf.py
+++ b/tab2opf.py
@@ -183,7 +183,7 @@ def readkeys():
 def writekeyfile(name, i):
     fname = "{}{}.html".format(name, i)
     if VERBOSE: print("Key file: {}".format(fname))
-    with open(fname, 'w') as to:
+    with open(fname, 'w', encoding='utf-8') as to:
         to.write("""<?xml version="1.0" encoding="utf-8"?>
 <html xmlns:idx="www.mobipocket.com" xmlns:mbp="www.mobipocket.com" xmlns:xlink="http://www.w3.org/1999/xlink">
   <body>
