diff --git a/Lib/fontTools/ufoLib/__init__.py b/Lib/fontTools/ufoLib/__init__.py
index ac052b2c1..667cb9d3d 100755
--- a/Lib/fontTools/ufoLib/__init__.py
+++ b/Lib/fontTools/ufoLib/__init__.py
@@ -107,7 +107,7 @@ class UFOFileStructure(enum.Enum):
 # --------------
 
 
-class _ModTimeGetterMixin(object):
+class _UFOBaseIO(object):
 
 	def _getFileModificationTime(self, path):
 		"""
@@ -123,9 +123,6 @@ class _ModTimeGetterMixin(object):
 		else:
 			return datetimeAsTimestamp(dt)
 
-
-class _PlistReaderMixin(object):
-
 	def _getPlist(self, fileName, default=None):
 		"""
 		Read a property list relative to the UFO filesystem's root.
@@ -153,9 +150,6 @@ class _PlistReaderMixin(object):
 				"'%s' could not be read on %s: %s" % (fileName, self.fs, e)
 			)
 
-
-class _PlistWriterMixin(object):
-
 	def _writePlist(self, fileName, obj):
 		"""
 		Write a property list to a file relative to the UFO filesystem's root.
@@ -198,7 +192,7 @@ class _PlistWriterMixin(object):
 # UFO Reader
 # ----------
 
-class UFOReader(_PlistReaderMixin, _ModTimeGetterMixin):
+class UFOReader(_UFOBaseIO):
 
 	"""
 	Read the various components of the .ufo.
@@ -811,7 +805,7 @@ class UFOReader(_PlistReaderMixin, _ModTimeGetterMixin):
 # UFO Writer
 # ----------
 
-class UFOWriter(_PlistWriterMixin, UFOReader):
+class UFOWriter(UFOReader):
 
 	"""
 	Write the various components of the .ufo.
diff --git a/Lib/fontTools/ufoLib/glifLib.py b/Lib/fontTools/ufoLib/glifLib.py
index eafeaa1fc..0556ce279 100755
--- a/Lib/fontTools/ufoLib/glifLib.py
+++ b/Lib/fontTools/ufoLib/glifLib.py
@@ -34,7 +34,7 @@ from fontTools.ufoLib.validators import (
 	glyphLibValidator,
 )
 from fontTools.misc import etree
-from fontTools.ufoLib import _PlistReaderMixin, _PlistWriterMixin, _ModTimeGetterMixin
+from fontTools.ufoLib import _UFOBaseIO
 from fontTools.ufoLib.utils import integerTypes, numberTypes
 
 
@@ -89,7 +89,7 @@ class Glyph(object):
 # Glyph Set
 # ---------
 
-class GlyphSet(_PlistWriterMixin, _PlistReaderMixin, _ModTimeGetterMixin):
+class GlyphSet(_UFOBaseIO):
 
 	"""
 	GlyphSet manages a set of .glif files inside one directory.