diff --git a/source/simulation2/helpers/Render.cpp b/source/simulation2/helpers/Render.cpp
index 9fedea5fa5..0f2cd4213e 100644
--- a/source/simulation2/helpers/Render.cpp
+++ b/source/simulation2/helpers/Render.cpp
@@ -90,7 +90,7 @@ static void ConstructCircleOrClosedArc(
 	// Adapt the circle resolution to look reasonable for small and largeish radiuses
 	size_t numPoints = clamp((size_t)(radius*(end-start)), (size_t)12, (size_t)48);
 
-	if (isCircle)
+	if (!isCircle)
 		overlay.m_Coords.reserve((numPoints + 1 + 2) * 3);
 	else
 		overlay.m_Coords.reserve((numPoints + 1) * 3);