diff --git a/Lib/fontTools/ufoLib/glifLib.py b/Lib/fontTools/ufoLib/glifLib.py
index 44622a148..89c9176a7 100755
--- a/Lib/fontTools/ufoLib/glifLib.py
+++ b/Lib/fontTools/ufoLib/glifLib.py
@@ -95,11 +95,11 @@ class Glyph:
 		self.glyphName = glyphName
 		self.glyphSet = glyphSet
 
-	def draw(self, pen):
+	def draw(self, pen, outputImpliedClosingLine=False):
 		"""
 		Draw this glyph onto a *FontTools* Pen.
 		"""
-		pointPen = PointToSegmentPen(pen)
+		pointPen = PointToSegmentPen(pen, outputImpliedClosingLine=outputImpliedClosingLine)
 		self.drawPoints(pointPen)
 
 	def drawPoints(self, pointPen):
diff --git a/Lib/fontTools/varLib/interpolatable.py b/Lib/fontTools/varLib/interpolatable.py
index 2954a15cb..03a8ca807 100644
--- a/Lib/fontTools/varLib/interpolatable.py
+++ b/Lib/fontTools/varLib/interpolatable.py
@@ -166,7 +166,10 @@ def test(glyphsets, glyphs=None, names=None):
                 perContourPen = PerContourOrComponentPen(
                     RecordingPen, glyphset=glyphset
                 )
-                glyph.draw(perContourPen)
+                try:
+                    glyph.draw(perContourPen, outputImpliedClosingLine=True)
+                except TypeError:
+                    glyph.draw(perContourPen)
                 contourPens = perContourPen.value
                 del perContourPen