1 files changed, 1 insertions, 1 deletions

diff --git a/src/ui.py b/src/ui.py
index 7803d3d..1e27ead 100644
--- a/src/ui.py
+++ b/src/ui.py
@@ -356,7 +356,7 @@ def optimize(which):
 	def I(theta):
 		op.angle = theta
 		if op.ref is not False:
-			op.ref += system.elements[op.ref].angle
+			op.angle += system.elements[op.ref].angle
 
 		state = None
 		for i, pol in enumerate(system.elements):