diff --git a/orx-shapes/src/commonMain/kotlin/adjust/ContourAdjuster.kt b/orx-shapes/src/commonMain/kotlin/adjust/ContourAdjuster.kt
index 2ff88d01..773f0391 100644
--- a/orx-shapes/src/commonMain/kotlin/adjust/ContourAdjuster.kt
+++ b/orx-shapes/src/commonMain/kotlin/adjust/ContourAdjuster.kt
@@ -32,7 +32,7 @@ class ContourAdjuster(var contour: ShapeContour) {
     /**
      * selected vertex indices
      */
-    var vertexSelection = List(contour.segments.size + if (contour.closed) 1 else 0) { it }
+    var vertexSelection = List(contour.segments.size + if (contour.closed) 0 else 1) { it }
 
     /**
      * selected edge indices
diff --git a/orx-shapes/src/commonMain/kotlin/adjust/ContourEdge.kt b/orx-shapes/src/commonMain/kotlin/adjust/ContourEdge.kt
index cfa4e397..73915f8c 100644
--- a/orx-shapes/src/commonMain/kotlin/adjust/ContourEdge.kt
+++ b/orx-shapes/src/commonMain/kotlin/adjust/ContourEdge.kt
@@ -233,8 +233,10 @@ data class ContourEdge(
             } else {
                 refIn.cubic.control
             }
-            control[1] = control[1].transformedBy(transform)
-            newSegments[segmentInIndex] = refIn.copy(end = segment.start.transformedBy(transform), control = control)
+            if (control.isNotEmpty()) {
+                control[1] = control[1].transformedBy(transform)
+            }
+            newSegments[segmentInIndex] = refIn.copy(end = segment.start.transformedBy(transform))
         }
         if (refOut != null) {
             val control = if (refOut.linear || !updateTangents) {
@@ -242,7 +244,9 @@ data class ContourEdge(
             } else {
                 refOut.cubic.control
             }
-            control[0] = control[0].transformedBy(transform)
+            if (control.isNotEmpty()) {
+                control[0] = control[0].transformedBy(transform)
+            }
             newSegments[segmentOutIndex] = refOut.copy(start = segment.end.transformedBy(transform))
         }
 
diff --git a/orx-shapes/src/jvmTest/kotlin/TestAdjustContour.kt b/orx-shapes/src/jvmTest/kotlin/TestAdjustContour.kt
new file mode 100644
index 00000000..8ac90e0e
--- /dev/null
+++ b/orx-shapes/src/jvmTest/kotlin/TestAdjustContour.kt
@@ -0,0 +1,96 @@
+import org.openrndr.extra.shapes.adjust.adjustContour
+import org.openrndr.math.Vector2
+import org.openrndr.shape.LineSegment
+import org.openrndr.shape.Rectangle
+import kotlin.math.cos
+import kotlin.math.sin
+import kotlin.test.Test
+import kotlin.test.assertEquals
+
+
+class TestAdjustContour {
+    @Test
+    fun testSingleLinearSegment() {
+        val adjusted = adjustContour(LineSegment(0.0, 0.0, 100.0, 100.0).contour) {
+            selectVertex(0)
+            vertex.moveTo(Vector2(50.0, 50.0))
+
+            selectVertex(1)
+            vertex.moveTo(Vector2(150.0, 150.0))
+        }
+        assertEquals(1, adjusted.segments.size)
+        assertEquals(50.0, adjusted.segments[0].start.x, 1E-6)
+        assertEquals(50.0, adjusted.segments[0].start.y, 1E-6)
+        assertEquals(150.0, adjusted.segments[0].end.x, 1E-6)
+        assertEquals(150.0, adjusted.segments[0].end.y, 1E-6)
+    }
+
+    @Test
+    fun testSingleLinearSegmentDefaultVertexSelection() {
+        val adjusted = adjustContour(LineSegment(0.0, 0.0, 100.0, 100.0).contour) {
+            for (v in vertices) {
+                v.moveBy(Vector2(50.0, 50.0))
+            }
+        }
+        assertEquals(1, adjusted.segments.size)
+        assertEquals(50.0, adjusted.segments[0].start.x, 1E-6)
+        assertEquals(50.0, adjusted.segments[0].start.y, 1E-6)
+        assertEquals(150.0, adjusted.segments[0].end.x, 1E-6)
+        assertEquals(150.0, adjusted.segments[0].end.y, 1E-6)
+    }
+
+    @Test
+    fun testSingleLinearSegmentDefaultEdgeSelection() {
+        val adjusted = adjustContour(LineSegment(0.0, 0.0, 100.0, 100.0).contour) {
+            for (e in edges) {
+                e.moveBy(Vector2(50.0, 50.0))
+            }
+        }
+        assertEquals(1, adjusted.segments.size)
+        assertEquals(50.0, adjusted.segments[0].start.x, 1E-6)
+        assertEquals(50.0, adjusted.segments[0].start.y, 1E-6)
+        assertEquals(150.0, adjusted.segments[0].end.x, 1E-6)
+        assertEquals(150.0, adjusted.segments[0].end.y, 1E-6)
+    }
+
+
+    @Test
+    fun testSingleQuadraticSegment() {
+        val adjusted = adjustContour(LineSegment(0.0, 0.0, 100.0, 100.0).segment.quadratic.contour) {
+            selectVertex(0)
+            vertex.moveTo(Vector2(50.0, 50.0))
+
+            selectVertex(1)
+            vertex.moveTo(Vector2(150.0, 150.0))
+        }
+        assertEquals(1, adjusted.segments.size)
+        assertEquals(50.0, adjusted.segments[0].start.x, 1E-6)
+        assertEquals(50.0, adjusted.segments[0].start.y, 1E-6)
+        assertEquals(150.0, adjusted.segments[0].end.x, 1E-6)
+        assertEquals(150.0, adjusted.segments[0].end.y, 1E-6)
+    }
+
+    @Test
+    fun testEdgeTransform() {
+        val adjusted = adjustContour(LineSegment(0.0, 0.0, 100.0, 100.0).segment.quadratic.contour) {
+            for (e in edges) {
+                e.moveBy(Vector2(50.0, 50.0))
+            }
+        }
+    }
+
+    @Test
+    fun testRectangleEdgeTransform() {
+        var r = Rectangle(0.0, 0.0, 400.0, 400.0).contour
+        val seconds = 0.0
+        r = adjustContour(r) {
+            selectEdge(1)
+            for (edge in edges) {
+                edge.moveBy(Vector2(sin(seconds) * 10.0, cos(seconds) * 5.0))
+            }
+        }
+
+
+    }
+
+}
\ No newline at end of file