diff --git a/Lib/fontTools/ttLib/tables/_g_v_a_r.py b/Lib/fontTools/ttLib/tables/_g_v_a_r.py
index 57f6f446d..4339ef0db 100644
--- a/Lib/fontTools/ttLib/tables/_g_v_a_r.py
+++ b/Lib/fontTools/ttLib/tables/_g_v_a_r.py
@@ -205,10 +205,11 @@ class table__g_v_a_r(DefaultTable.DefaultTable):
 			coord = sharedCoords[flags & TUPLE_INDEX_MASK]
 		else:
 			coord, pos = GlyphVariation.decompileCoord_(axisTags, data, pos)
-		minCoord = maxCoord = coord
 		if (flags & INTERMEDIATE_TUPLE) != 0:
 			minCoord, pos = GlyphVariation.decompileCoord_(axisTags, data, pos)
 			maxCoord, pos = GlyphVariation.decompileCoord_(axisTags, data, pos)
+		else:
+			minCoord, maxCoord = table__g_v_a_r.computeMinMaxCoord_(coord)
 		axes = {}
 		for axis in axisTags:
 			coords = minCoord[axis], coord[axis], maxCoord[axis]
@@ -226,6 +227,15 @@ class table__g_v_a_r(DefaultTable.DefaultTable):
 				deltas[p] = (x, y)
 		return GlyphVariation(axes, deltas)
 
+	@staticmethod
+	def computeMinMaxCoord_(coord):
+		minCoord = {}
+		maxCoord = {}
+		for (axis, value) in coord.iteritems():
+			minCoord[axis] = min(value, 0.0)  # -0.3 --> -0.3; 0.7 --> 0.0
+			maxCoord[axis] = max(value, 0.0)  # -0.3 -->  0.0; 0.7 --> 0.7
+		return (minCoord, maxCoord)
+
 	def toXML(self, writer, ttFont):
 		writer.simpletag("version", value=self.version)
 		writer.newline()
@@ -293,7 +303,9 @@ class GlyphVariation:
 			value = self.axes.get(axis)
 			if value != None:
 				minValue, value, maxValue = value
-				if minValue == value and maxValue == value:
+				defaultMinValue = min(value, 0.0)  # -0.3 --> -0.3; 0.7 --> 0.0
+				defaultMaxValue = max(value, 0.0)  # -0.3 -->  0.0; 0.7 --> 0.7
+				if minValue == defaultMinValue and maxValue == defaultMaxValue:
 					writer.simpletag("coord", axis=axis, value=value)
 				else:
 					writer.simpletag("coord", axis=axis, value=value,
@@ -315,10 +327,12 @@ class GlyphVariation:
 	def fromXML(self, name, attrs, content):
 		if name == "coord":
 			axis = attrs["axis"]
-			value = attrs["value"]
-			minValue = attrs.get("min", value)
-			maxValue = attrs.get("max", value)
-			self.axes[axis] = (safeEval(minValue), safeEval(value), safeEval(maxValue))
+			value = float(attrs["value"])
+			defaultMinValue = min(value, 0.0)  # -0.3 --> -0.3; 0.7 --> 0.0
+			defaultMaxValue = max(value, 0.0)  # -0.3 -->  0.0; 0.7 --> 0.7
+			minValue = float(attrs.get("min", defaultMinValue))
+			maxValue = float(attrs.get("max", defaultMaxValue))
+			self.axes[axis] = (minValue, value, maxValue)
 		elif name == "delta":
 			point = safeEval(attrs["pt"])
 			x = safeEval(attrs["x"])
@@ -336,7 +350,9 @@ class GlyphVariation:
 		needed = False
 		for axis in axisTags:
 			minValue, value, maxValue = self.axes.get(axis, (0.0, 0.0, 0.0))
-			if (minValue != value) or (maxValue != value):
+			defaultMinValue = min(value, 0.0)  # -0.3 --> -0.3; 0.7 --> 0.0
+			defaultMaxValue = max(value, 0.0)  # -0.3 -->  0.0; 0.7 --> 0.7
+			if (minValue != defaultMinValue) or (maxValue != defaultMaxValue):
 				needed = True
 				break
 		if not needed:
diff --git a/Lib/fontTools/ttLib/tables/_g_v_a_r_test.py b/Lib/fontTools/ttLib/tables/_g_v_a_r_test.py
index c8babf87a..f43bff229 100644
--- a/Lib/fontTools/ttLib/tables/_g_v_a_r_test.py
+++ b/Lib/fontTools/ttLib/tables/_g_v_a_r_test.py
@@ -126,7 +126,7 @@ class GlyphVariationTableTest(unittest.TestCase):
 		sharedCoords = table.decompileSharedCoords_(axes, SKIA_SHARED_COORDS)
 		tuples = table.decompileTuples_(18, sharedCoords, axes, SKIA_GVAR_I)
 		self.assertEqual(8, len(tuples))
-		self.assertEqual({"wght": (1.0, 1.0, 1.0)}, tuples[0].axes)
+		self.assertEqual({"wght": (0.0, 1.0, 1.0)}, tuples[0].axes)
 		self.assertEqual("257,0 -127,0 -128,58 -130,90 -130,62 -130,67 -130,32 -127,0 257,0 "
 				 "259,14 260,64 260,21 260,69 258,124 0,0 130,0 0,0 0,0",
 				 " ".join(["%d,%d" % c for c in tuples[0].coordinates]))
@@ -135,17 +135,23 @@ class GlyphVariationTableTest(unittest.TestCase):
 		table = table__g_v_a_r()
 		self.assertEqual([], table.decompileTuples_(numPoints=5, sharedCoords=[], axisTags=[], data=b""))
 
+	def test_computeMinMaxCord(self):
+		coord = {"wght": -0.3, "wdth": 0.7}
+		minCoord, maxCoord = table__g_v_a_r.computeMinMaxCoord_(coord)
+		self.assertEqual({"wght": -0.3, "wdth": 0.0}, minCoord)
+		self.assertEqual({"wght": 0.0, "wdth": 0.7}, maxCoord)
 
 class GlyphVariationTest(unittest.TestCase):
 	def test_toXML(self):
 		writer = XMLWriter(StringIO())
-		axes = {"wdth":(0.3, 0.4, 0.5), "wght":(1.0, 1.0, 1.0)}
+		axes = {"wdth":(0.3, 0.4, 0.5), "wght":(0.0, 1.0, 1.0), "opsz":(-0.7, -0.7, 0.0)}
 		g = GlyphVariation(axes, GlyphCoordinates([(9,8), (7,6), (0,0), (-1,-2)]))
-		g.toXML(writer, ["wght", "wdth"])
+		g.toXML(writer, ["wdth", "wght", "opsz"])
 		self.assertEqual([
 			'<tuple>',
-			  '<coord axis="wght" value="1.0"/>',
 			  '<coord axis="wdth" max="0.5" min="0.3" value="0.4"/>',
+			  '<coord axis="wght" value="1.0"/>',
+			  '<coord axis="opsz" value="-0.7"/>',
 			  '<delta pt="0" x="9" y="8"/>',
 			  '<delta pt="1" x="7" y="6"/>',
 			  '<delta pt="3" x="-1" y="-2"/>',
@@ -154,24 +160,28 @@ class GlyphVariationTest(unittest.TestCase):
 
 	def test_toXML_allDeltasZero(self):
 		writer = XMLWriter(StringIO())
-		axes = {"wdth":(0.3, 0.4, 0.5), "wght":(1.0, 1.0, 1.0)}
+		axes = {"wght":(0.0, 1.0, 1.0)}
 		g = GlyphVariation(axes, GlyphCoordinates.zeros(5))
 		g.toXML(writer, ["wght", "wdth"])
 		self.assertEqual([
 			'<tuple>',
 			  '<coord axis="wght" value="1.0"/>',
-			  '<coord axis="wdth" max="0.5" min="0.3" value="0.4"/>',
 			  '<!-- all deltas are (0,0) -->',
 			'</tuple>'
 		], GlyphVariationTest.xml_lines(writer))
 
 	def test_fromXML(self):
 		g = GlyphVariation({}, GlyphCoordinates.zeros(4))
-		g.fromXML("coord", {"axis":"wght", "value":"1.0"}, [])
 		g.fromXML("coord", {"axis":"wdth", "min":"0.3", "value":"0.4", "max":"0.5"}, [])
+		g.fromXML("coord", {"axis":"wght", "value":"1.0"}, [])
+		g.fromXML("coord", {"axis":"opsz", "value":"-0.5"}, [])
 		g.fromXML("delta", {"pt":"1", "x":"33", "y":"44"}, [])
 		g.fromXML("delta", {"pt":"2", "x":"-2", "y":"170"}, [])
-		self.assertEqual({"wght":(1.0, 1.0, 1.0), "wdth":(0.3, 0.4, 0.5)}, g.axes)
+		self.assertEqual({
+			"wdth":( 0.3,  0.4, 0.5),
+			"wght":( 0.0,  1.0, 1.0),
+			"opsz":(-0.5, -0.5, 0.0)
+		}, g.axes)
 		self.assertEqual("0,0 33,44 -2,170 0,0", " ".join(["%d,%d" % c for c in g.coordinates]))
 
 	def test_compileCoord(self):
@@ -181,9 +191,9 @@ class GlyphVariationTest(unittest.TestCase):
 		self.assertEqual("C0 00", hexencode(gvar.compileCoord(["wght"])))
 
 	def test_compileIntermediateCoord(self):
-		gvar = GlyphVariation({"wght": (-1.0, -1.0, -1.0), "wdth": (0.4, 0.5, 0.6)}, GlyphCoordinates.zeros(4))
-		self.assertEqual("C0 00 19 9A C0 00 26 66", hexencode(gvar.compileIntermediateCoord(["wght", "wdth"])))
-		self.assertEqual("19 9A C0 00 26 66 C0 00", hexencode(gvar.compileIntermediateCoord(["wdth", "wght"])))
+		gvar = GlyphVariation({"wght": (-1.0, -1.0, 0.0), "wdth": (0.4, 0.5, 0.6)}, GlyphCoordinates.zeros(4))
+		self.assertEqual("C0 00 19 9A 00 00 26 66", hexencode(gvar.compileIntermediateCoord(["wght", "wdth"])))
+		self.assertEqual("19 9A C0 00 26 66 00 00", hexencode(gvar.compileIntermediateCoord(["wdth", "wght"])))
 		self.assertEqual(None, gvar.compileIntermediateCoord(["wght"]))
 		self.assertEqual("19 9A 26 66", hexencode(gvar.compileIntermediateCoord(["wdth"])))