diff --git a/gluish/format.py b/gluish/format.py
index <HASH>..<HASH> 100644
--- a/gluish/format.py
+++ b/gluish/format.py
@@ -58,7 +58,7 @@ def write_tsv(output_stream, *tup, **kwargs):
     Write argument list in `tup` out as a tab-separeated row to the stream.
     """
     encoding = kwargs.get('encoding') or 'utf-8'
-    value = '\t'.join([s for s in tup]) + '\n'
+    value = u'\t'.join([s for s in tup]) + '\n'
     output_stream.write(value.encode(encoding))
write_tsv: join with unicode