diff --git a/Lib/fontTools/ufoLib/__init__.py b/Lib/fontTools/ufoLib/__init__.py
index 26b7ddd3e..4a1fa864d 100755
--- a/Lib/fontTools/ufoLib/__init__.py
+++ b/Lib/fontTools/ufoLib/__init__.py
@@ -1391,7 +1391,7 @@ class UFOWriter(UFOReader):
 	def _getGlyphSetFormatVersion1(self, validateRead, validateWrite, glyphNameToFileNameFunc=None):
 		from fontTools.ufoLib.glifLib import GlyphSet
 
-		glyphSubFS = self.fs.makedir(DEFAULT_GLYPHS_DIRNAME, recreate=True),
+		glyphSubFS = self.fs.makedir(DEFAULT_GLYPHS_DIRNAME, recreate=True)
 		return GlyphSet(
 			glyphSubFS,
 			glyphNameToFileNameFunc=glyphNameToFileNameFunc,