diff --git a/Lib/fontTools/ttLib/ttCollection.py b/Lib/fontTools/ttLib/ttCollection.py
index 7f2eb67fe..2507fe306 100644
--- a/Lib/fontTools/ttLib/ttCollection.py
+++ b/Lib/fontTools/ttLib/ttCollection.py
@@ -64,7 +64,6 @@ class TTCollection(object):
 		file.write(struct.pack(">%dL" % len(self.fonts), *offsets))
 
 		if final:
-			final.seek(0)
 			final.write(file.getvalue())
 		file.close()