diff --git a/src/calibre/customize/builtins.py b/src/calibre/customize/builtins.py
index 04e880b714..b56d015e54 100644
--- a/src/calibre/customize/builtins.py
+++ b/src/calibre/customize/builtins.py
@@ -423,6 +423,17 @@ class TOPAZMetadataWriter(MetadataWriterPlugin):
         from calibre.ebooks.metadata.topaz import set_metadata
         set_metadata(stream, mi)
 
+class TXTZMetadataWriter(MetadataWriterPlugin):
+
+    name        = 'Set TXTZ metadata'
+    file_types  = set(['txtz'])
+    description = _('Set metadata from %s files') % 'TXTZ'
+    author      = 'John Schember'
+
+    def set_metadata(self, stream, mi, type):
+        from calibre.ebooks.metadata.txtz import set_metadata
+        set_metadata(stream, mi)
+
 # }}}
 
 from calibre.ebooks.comic.input import ComicInput
diff --git a/src/calibre/ebooks/metadata/txtz.py b/src/calibre/ebooks/metadata/txtz.py
index b9d607c63b..ba0078328e 100644
--- a/src/calibre/ebooks/metadata/txtz.py
+++ b/src/calibre/ebooks/metadata/txtz.py
@@ -9,9 +9,12 @@ Read meta information from TXT files
 
 import os
 
+from cStringIO import StringIO
+
 from calibre.ebooks.metadata import MetaInformation
+from calibre.ebooks.metadata.opf2 import OPF, metadata_to_opf
 from calibre.ptempfile import TemporaryDirectory
-from calibre.utils.zipfile import ZipFile
+from calibre.utils.zipfile import ZipFile, safe_replace
 
 def get_metadata(stream, extract_cover=True):
     '''
@@ -24,11 +27,13 @@ def get_metadata(stream, extract_cover=True):
         try:
             zf = ZipFile(stream)
             zf.extract('metadata.opf', tdir)
-            
-            from calibre.ebooks.metadata.opf2 import OPF
             with open(os.path.join(tdir, 'metadata.opf'), 'rb') as opff:
                 mi = OPF(opff).to_book_metadata()
         except:
             return mi
-
     return mi
+
+def set_metadata(stream, mi):
+    stream.seek(0)
+    opf = StringIO(metadata_to_opf(mi))
+    safe_replace(stream, 'metadata.opf', opf)