diff --git a/Source/Core/Rendering/Renderer2D.cs b/Source/Core/Rendering/Renderer2D.cs
index 04a6d7f..9f4c744 100644
--- a/Source/Core/Rendering/Renderer2D.cs
+++ b/Source/Core/Rendering/Renderer2D.cs
@@ -1460,20 +1460,39 @@ namespace CodeImp.DoomBuilder.Rendering
 			int i = 0;
 			int size = waypoints.Count;
 			int seqStart = 0;
+			TextLabel[] sequencelabels = new TextLabel[256];
 			while (i < size - 1)
 			{
 				int iNext = i + 1;
-				if (waypoints[i].AngleDoom % 256 == 0)
+				if (waypoints[i].AngleDoom % 256 == 0) // start of a new sequence?
+				{
 					seqStart = i;
+					sequencelabels[waypoints[i].AngleDoom / 256] = new TextLabel(3) // create sequence ID label
+					{
+						Text = (waypoints[i].AngleDoom / 256).ToString(),
+						AlignX = TextAlignmentX.Center,
+						AlignY = TextAlignmentY.Middle,
+						Color = General.Colors.WaypointColor,
+						Backcolor = General.Colors.Background,
+						Scale = 16f,
+						TransformCoords = true,
+						Rectangle = new RectangleF(waypoints[i].Position.x, waypoints[i].Position.y, 0.0f, 0.0f)
+					};
+				}
 				if (iNext < size && waypoints[iNext].AngleDoom == waypoints[i].AngleDoom + 1) // next waypoint of this sequence?
 					RenderLine((Vector2D)waypoints[i].Position, (Vector2D)waypoints[iNext].Position, 1.5f, General.Colors.WaypointColor, true);
+				else if (iNext < size && waypoints[iNext].AngleDoom == waypoints[i].AngleDoom) // mark duplicate waypoints
+					RenderCircle((Vector2D)waypoints[iNext].Position, 32f, 1f, PixelColor.FromColor(Color.Red), true);
 				else // draw different line between last and first waypoint of this sequence
 					RenderLine((Vector2D)waypoints[i].Position, (Vector2D)waypoints[seqStart].Position, 0.75f, General.Colors.WaypointLoopColor, true);
 				i = iNext;
 			}
 
-            //Render axis transfer lines.
-            i = 0;
+			for (i = 0; i < 256; i++)
+				if (sequencelabels[i] != null) RenderText(sequencelabels[i]);
+
+			//Render axis transfer lines.
+			i = 0;
             size = axistransferlines.Count;
             while (i < size - 1)
             {