diff --git a/Lib/fontTools/ttLib/tables/_g_l_y_f.py b/Lib/fontTools/ttLib/tables/_g_l_y_f.py
index 46cb2fd61..5c0e5f7f8 100644
--- a/Lib/fontTools/ttLib/tables/_g_l_y_f.py
+++ b/Lib/fontTools/ttLib/tables/_g_l_y_f.py
@@ -372,7 +372,7 @@ class table__g_l_y_f(DefaultTable.DefaultTable):
         ]
 
     def _getCoordinatesAndControls(
-        self, glyphName, hMetrics, vMetrics=None, roundCoordinates=True
+        self, glyphName, hMetrics, vMetrics=None, *, round=otRound
     ):
         """Return glyph coordinates and controls as expected by "gvar" table.
 
@@ -446,8 +446,7 @@ class table__g_l_y_f(DefaultTable.DefaultTable):
         # Add phantom points for (left, right, top, bottom) positions.
         phantomPoints = self._getPhantomPoints(glyphName, hMetrics, vMetrics)
         coords.extend(phantomPoints)
-        if roundCoordinates:
-            coords.toInt()
+        coords.toInt(round=round)
         return coords, controls
 
     def _setCoordinates(self, glyphName, coord, hMetrics, vMetrics=None):
diff --git a/Tests/varLib/instancer/instancer_test.py b/Tests/varLib/instancer/instancer_test.py
index e574384de..ab64c379d 100644
--- a/Tests/varLib/instancer/instancer_test.py
+++ b/Tests/varLib/instancer/instancer_test.py
@@ -1,4 +1,5 @@
 from fontTools.misc.fixedTools import floatToFixedToFloat
+from fontTools.misc.roundTools import noRound
 from fontTools.misc.testTools import stripVariableItemsFromTTX
 from fontTools.misc.textTools import Tag
 from fontTools import ttLib
@@ -57,7 +58,7 @@ def _get_coordinates(varfont, glyphname):
             varfont["hmtx"].metrics,
             varfont["vmtx"].metrics,
             # the tests expect float coordinates
-            roundCoordinates=False,
+            round=noRound,
         )[0]
     )