diff --git a/glyphs/overmarks.ptl b/glyphs/overmarks.ptl
index bb97933ba..36ccf6e9a 100644
--- a/glyphs/overmarks.ptl
+++ b/glyphs/overmarks.ptl
@@ -4,7 +4,7 @@ import '../support/transform' as : Transform && [object [transformPoint tp]]
 import [curveToContour OffsetCurve] from '../support/curve-util'
 import [mix linreg clamp fallback] from '../support/utils'
 import [designParameters] from '../meta/aesthetics'
-import [Curve Quadify] from "typo-geom"
+import [Arc Quadify] from "typo-geom"
 import [TieMark TieGlyph] from "../support/gr"
 
 glyph-module
@@ -225,7 +225,7 @@ glyph-block Overmarks : begin
 		define z2 : tp currentGlyph.gizmo : object [x : mix leftEnd rightEnd tildeWaveX] [y : mix tbot ttop tildeWave]
 		define z3 : tp currentGlyph.gizmo : object [x : mix leftEnd rightEnd (1 - tildeWaveX)] [y : mix tbot ttop (1 - tildeWave)]
 		define z4 : tp currentGlyph.gizmo : object [x rightEnd] [y ttop]
-		define bone : new Curve.Bez3 z1 z2 z3 z4
+		define bone : new Arc.Bez3 z1 z2 z3 z4
 
 		define inner : curveToContour [new OffsetCurve bone (+hs) HVContrast] 32
 		define outer : curveToContour [new OffsetCurve bone (-hs) HVContrast] 32
diff --git a/package.json b/package.json
index 4df9631b3..91d2acd3d 100644
--- a/package.json
+++ b/package.json
@@ -21,7 +21,7 @@
 		"topsort": "^0.0.2",
 		"ttf2woff": "^2.0.1",
 		"ttf2woff2": "^3.0.0",
-		"typo-geom": "^0.5.1",
+		"typo-geom": "^0.6.0",
 		"unicode-13.0.0": "^0.8.0",
 		"unorm": "^1.6.0",
 		"verda": "^1.0.1",
diff --git a/support/curve-util.js b/support/curve-util.js
index 9d5e352f8..c9ffc250d 100644
--- a/support/curve-util.js
+++ b/support/curve-util.js
@@ -182,7 +182,7 @@ function autoCubify(arc, err) {
 			if (s > 0) offPoints.push(z0);
 			offPoints.push(z1, z2);
 
-			const bezArc = new typoGeom.Curve.Bez3(z0, z1, z2, z3);
+			const bezArc = new typoGeom.Arc.Bez3(z0, z1, z2, z3);
 
 			for (let k = 1; k < perSegHits; k++) {
 				const tk = k / perSegHits;
diff --git a/support/fairify.js b/support/fairify.js
index 323124a47..6d47d568a 100644
--- a/support/fairify.js
+++ b/support/fairify.js
@@ -201,7 +201,7 @@ class BezierCurveCluster {
 			if (zs[j].on) {
 				const z1 = last,
 					z4 = zs[j];
-				const seg = new typoGeom.Curve.StraightSegment(z1, z4);
+				const seg = new typoGeom.Arc.StraightSegment(z1, z4);
 				segments.push(seg);
 				lengths.push(this.measureLength(seg));
 				last = z4;
@@ -210,7 +210,7 @@ class BezierCurveCluster {
 					z2 = zs[j],
 					z3 = zs[j + 1],
 					z4 = zs[j + 2];
-				const seg = new typoGeom.Curve.Bez3(z1, z2, z3, z4);
+				const seg = new typoGeom.Arc.Bez3(z1, z2, z3, z4);
 				segments.push(seg);
 				lengths.push(this.measureLength(seg));
 				last = z4;