diff --git a/src/main/kotlin/ru/dbotthepony/mc/otm/client/render/GraphRendering.kt b/src/main/kotlin/ru/dbotthepony/mc/otm/client/render/GraphRendering.kt
index d8ef7fe50..c20392fce 100644
--- a/src/main/kotlin/ru/dbotthepony/mc/otm/client/render/GraphRendering.kt
+++ b/src/main/kotlin/ru/dbotthepony/mc/otm/client/render/GraphRendering.kt
@@ -63,16 +63,23 @@ fun renderGraph(
 		val xDiff = x1 - x0
 		val yDiff = y1 - y0
 
-		val length = (xDiff.pow(2f) + yDiff.pow(2f)).pow(0.5f)
-		val angle = acos(xDiff / length) * yDiff.sign - PI / 2f // rotate 90 deg
+		if (yDiff.sign == 0f) {
+			builder.vertex(pose, x0, y0 + LINE_WIDTH / 2f, 0f)
+			builder.vertex(pose, x0, y0 - LINE_WIDTH / 2f, 0f)
+			builder.vertex(pose, x1, y1 - LINE_WIDTH / 2f, 0f)
+			builder.vertex(pose, x1, y1 + LINE_WIDTH / 2f, 0f)
+		} else {
+			val length = (xDiff.pow(2f) + yDiff.pow(2f)).pow(0.5f)
+			val angle = acos(xDiff / length) * yDiff.sign - PI / 2f // rotate 90 deg
 
-		val xDisp = cos(angle).toFloat() * LINE_WIDTH / 2f
-		val yDisp = sin(angle).toFloat() * LINE_WIDTH / 2f
+			val xDisp = cos(angle).toFloat() * LINE_WIDTH / 2f
+			val yDisp = sin(angle).toFloat() * LINE_WIDTH / 2f
 
-		builder.vertex(pose, x1 - xDisp, y1 + yDisp, 0f)
-		builder.vertex(pose, x1 + xDisp, y1 - yDisp, 0f)
-		builder.vertex(pose, x0 + xDisp, y0 - yDisp, 0f)
-		builder.vertex(pose, x0 - xDisp, y0 + yDisp, 0f)
+			builder.vertex(pose, x0 + xDisp, y0 + yDisp, 0f)
+			builder.vertex(pose, x0 - xDisp, y0 - yDisp, 0f)
+			builder.vertex(pose, x1 - xDisp, y1 - yDisp, 0f)
+			builder.vertex(pose, x1 + xDisp, y1 + yDisp, 0f)
+		}
 
 		//graphics.renderRect(x0, y0, LINE_WIDTH, LINE_WIDTH)