diff --git a/Lib/fontTools/varLib/instancer/__init__.py b/Lib/fontTools/varLib/instancer/__init__.py
index 90555f380..909716ab3 100644
--- a/Lib/fontTools/varLib/instancer/__init__.py
+++ b/Lib/fontTools/varLib/instancer/__init__.py
@@ -248,7 +248,7 @@ def changeTupleVariationAxisLimit(var, axisTag, axisLimit):
     out = []
     for scalar,tent in solutions:
         newVar = TupleVariation(var.axes, var.coordinates) if len(solutions) > 1 else var
-        if tent[1] == 0:
+        if tent is None:
             newVar.axes.pop(axisTag)
         else:
             newVar.axes[axisTag] = tent
diff --git a/Lib/fontTools/varLib/instancer/solver.py b/Lib/fontTools/varLib/instancer/solver.py
index 5a956341a..136c92c47 100644
--- a/Lib/fontTools/varLib/instancer/solver.py
+++ b/Lib/fontTools/varLib/instancer/solver.py
@@ -47,7 +47,7 @@ def _solveWithGain(tent, axisLimit):
     # lower <= axisDef <= peak <= axisMax
 
     gain = supportScalar({'tag': axisDef}, {'tag': tent})
-    out = [(gain, axisLimit)]
+    out = [(gain, None)]
 
     # First, the positive side
 
@@ -137,7 +137,7 @@ def _solveGeneral(tent, axisLimit):
 
     # Mirror the problem such that axisDef is always <= peak
     if axisDef > peak:
-        return [(scalar, _revnegate(t))
+        return [(scalar, _revnegate(t) if t is not None else None)
                 for scalar,t
                 in _solveGeneral(_revnegate(tent),
                                  _revnegate(axisLimit))]
@@ -179,5 +179,5 @@ def rebaseTent(tent, axisLimit):
 
     sols = _solveGeneral(tent, axisLimit)
     n = lambda v: normalizeValue(v, axisLimit, extrapolate=True)
-    sols = [(scalar, (n(v[0]), n(v[1]), n(v[2]))) for scalar,v in sols if scalar != 0]
+    sols = [(scalar, (n(v[0]), n(v[1]), n(v[2])) if v is not None else None) for scalar,v in sols if scalar != 0]
     return sols
diff --git a/Tests/varLib/instancer/solver_test.py b/Tests/varLib/instancer/solver_test.py
index 048827a1f..b69dc2c04 100644
--- a/Tests/varLib/instancer/solver_test.py
+++ b/Tests/varLib/instancer/solver_test.py
@@ -25,7 +25,7 @@ class RebaseTentTest(object):
             pytest.param(
                 (0, 1, 1), (.5, .5, .5),
                 [
-                    (.5, (0, 0, 0)),
+                    (.5, None),
                 ]
             ),
 
@@ -88,7 +88,7 @@ class RebaseTentTest(object):
             pytest.param(
                 (.0, .5, 1), (0, .5, 1),
                 [
-                    (1, (-1, 0, 1)),
+                    (1, None),
                     (-1, (0, 1, 1)),
                     (-1, (-1, -1, 0)),
                 ]
@@ -98,7 +98,7 @@ class RebaseTentTest(object):
             pytest.param(
                 (.0, .5, 2), (.2, .5, .8),
                 [
-                    (1, (-1, 0, 1)),
+                    (1, None),
                     (-0.20000000000000007, (0, 1, 1)),
                     (-.6, (-1, -1, 0)),
                 ]
@@ -108,7 +108,7 @@ class RebaseTentTest(object):
             pytest.param(
                 (.0, .5, 2), (.2, .5, 1),
                 [
-                    (1, (-1, 0, 1)),
+                    (1, None),
                     (-0.33333333333333337, (0, 1, 1)),
                     (-.6, (-1, -1, 0)),
                 ]
@@ -118,7 +118,7 @@ class RebaseTentTest(object):
             pytest.param(
                 (.0, .5, 1), (0, .25, .5),
                 [
-                    (.5, (-1, 0, 1)),
+                    (.5, None),
                     (.5, (0, 1, 1)),
                     (-.5, (-1, -1, 0)),
                 ]
@@ -128,7 +128,7 @@ class RebaseTentTest(object):
             pytest.param(
                 (.05, .55, 1), (0, .25, .5),
                 [
-                    (.4, (-1.0, 0.0, 1.0)),
+                    (.4, None),
                     (.5, (0, 1, 1)),
                     (-.4, (-1, -.8, 0)),
                     (-.4, (-1, -1, -.8)),
@@ -139,7 +139,7 @@ class RebaseTentTest(object):
             pytest.param(
                 (-1, -.55, -.05), (-.5, -.25, 0),
                 [
-                    (.4, (-1.0, 0.0, 1.0)),
+                    (.4, None),
                     (.5, (-1, -1, 0)),
                     (-.4, (0, .8, 1)),
                     (-.4, (.8, 1, 1)),
@@ -153,14 +153,14 @@ class RebaseTentTest(object):
             pytest.param(
                 (.5, .5, .5), (.5, .5, .5),
                 [
-                    (1, (0, 0, 0)),
+                    (1, None),
                 ]
             ),
 
             pytest.param(
                 (.3, .5, .7), (.1, .5, .9),
                 [
-                    (1, (-1, 0, 1)),
+                    (1, None),
                     (-1, (0, 0.4999999999999999, 1)),
                     (-1, (0.4999999999999999, 1, 1)),
                     (-1, (-1, -.5, 0)),