diff --git a/Lib/fontTools/varLib/__init__.py b/Lib/fontTools/varLib/__init__.py
index 51de4aa9a..6ec4113ff 100644
--- a/Lib/fontTools/varLib/__init__.py
+++ b/Lib/fontTools/varLib/__init__.py
@@ -890,7 +890,7 @@ def load_masters(designspace, master_finder=lambda s: s):
 				# 2. A SourceDescriptor's path might point an OpenType binary, a
 				# TTX file, or another source file (e.g. UFO), in which case we
 				# resolve the path using 'master_finder' function
-				font = _open_font(master.path, master_finder)
+				master.font = font = _open_font(master.path, master_finder)
 				master_fonts.append(font)
 
 	return master_fonts
diff --git a/Tests/cffLib/cffLib_test.py b/Tests/cffLib/cffLib_test.py
index 1d169c9a6..ce73b3440 100644
--- a/Tests/cffLib/cffLib_test.py
+++ b/Tests/cffLib/cffLib_test.py
@@ -2,6 +2,8 @@ from __future__ import print_function, division, absolute_import
 from fontTools.cffLib import TopDict, PrivateDict, CharStrings
 from fontTools.misc.testTools import parseXML, DataFilesHandler
 from fontTools.ttLib import TTFont
+import copy
+import os
 import sys
 import unittest
 
@@ -59,6 +61,21 @@ class CffLibTest(DataFilesHandler):
         topDict2 = font2["CFF "].cff.topDictIndex[0]
         self.assertEqual(topDict2.Encoding[32], "space")
 
+    def test_CFF_deepcopy(self):
+        """Test that deepcopying a TTFont with a CFF table does not recurse
+        infinitely."""
+        ttx_path = os.path.join(
+            os.path.dirname(__file__),
+            "..",
+            "varLib",
+            "data",
+            "master_ttx_interpolatable_otf",
+            "TestFamily2-Master0.ttx",
+        )
+        font = TTFont(recalcBBoxes=False, recalcTimestamp=False)
+        font.importXML(ttx_path)
+        copy.deepcopy(font)
+
 
 if __name__ == "__main__":
     sys.exit(unittest.main())
diff --git a/Tests/varLib/interpolate_layout_test.py b/Tests/varLib/interpolate_layout_test.py
index 00039295c..b858a3c97 100644
--- a/Tests/varLib/interpolate_layout_test.py
+++ b/Tests/varLib/interpolate_layout_test.py
@@ -4,7 +4,7 @@ from fontTools.ttLib import TTFont
 from fontTools.varLib import build
 from fontTools.varLib.interpolate_layout import interpolate_layout
 from fontTools.varLib.interpolate_layout import main as interpolate_layout_main
-from fontTools.designspaceLib import DesignSpaceDocumentError
+from fontTools.designspaceLib import DesignSpaceDocument, DesignSpaceDocumentError
 from fontTools.feaLib.builder import addOpenTypeFeaturesFromString
 import difflib
 import os
diff --git a/Tests/varLib/varLib_test.py b/Tests/varLib/varLib_test.py
index e5776e347..32e7ab5e2 100644
--- a/Tests/varLib/varLib_test.py
+++ b/Tests/varLib/varLib_test.py
@@ -366,11 +366,11 @@ class BuildTest(unittest.TestCase):
 
         ds_path = self.get_test_input("SparseMasters.designspace")
         ds = DesignSpaceDocument.fromfile(ds_path)
-        masters = load_masters(ds)
+        load_masters(ds)
 
         # Trigger MVAR generation so varLib is forced to create deltas with a
         # sparse master inbetween.
-        font_0_os2 = masters[0]["OS/2"]
+        font_0_os2 = ds.sources[0].font["OS/2"]
         font_0_os2.sTypoAscender = 1
         font_0_os2.sTypoDescender = 1
         font_0_os2.sTypoLineGap = 1
@@ -395,16 +395,16 @@ class BuildTest(unittest.TestCase):
         font_0_vhea.caretSlopeRise = 1
         font_0_vhea.caretSlopeRun = 1
         font_0_vhea.caretOffset = 1
-        masters[0]["vhea"] = font_0_vhea
-        font_0_hhea = masters[0]["hhea"]
+        ds.sources[0].font["vhea"] = font_0_vhea
+        font_0_hhea = ds.sources[0].font["hhea"]
         font_0_hhea.caretSlopeRise = 1
         font_0_hhea.caretSlopeRun = 1
         font_0_hhea.caretOffset = 1
-        font_0_post = masters[0]["post"]
+        font_0_post = ds.sources[0].font["post"]
         font_0_post.underlineThickness = 1
         font_0_post.underlinePosition = 1
 
-        font_2_os2 = masters[2]["OS/2"]
+        font_2_os2 = ds.sources[2].font["OS/2"]
         font_2_os2.sTypoAscender = 800
         font_2_os2.sTypoDescender = 800
         font_2_os2.sTypoLineGap = 800
@@ -429,18 +429,15 @@ class BuildTest(unittest.TestCase):
         font_2_vhea.caretSlopeRise = 800
         font_2_vhea.caretSlopeRun = 800
         font_2_vhea.caretOffset = 800
-        masters[2]["vhea"] = font_2_vhea
-        font_2_hhea = masters[2]["hhea"]
+        ds.sources[2].font["vhea"] = font_2_vhea
+        font_2_hhea = ds.sources[2].font["hhea"]
         font_2_hhea.caretSlopeRise = 800
         font_2_hhea.caretSlopeRun = 800
         font_2_hhea.caretOffset = 800
-        font_2_post = masters[2]["post"]
+        font_2_post = ds.sources[2].font["post"]
         font_2_post.underlineThickness = 800
         font_2_post.underlinePosition = 800
 
-        for m, s in zip(masters, ds.sources):
-            s.font = m
-
         varfont, _, _ = build(ds)
         mvar_tags = [vr.ValueTag for vr in varfont["MVAR"].table.ValueRecord]
         assert all(tag in mvar_tags for tag in fontTools.varLib.mvar.MVAR_ENTRIES)