diff --git a/script/RFscan/GunScan.py b/script/RFscan/GunScan.py
index b64be12..afc989f 100644
--- a/script/RFscan/GunScan.py
+++ b/script/RFscan/GunScan.py
@@ -29,7 +29,7 @@ phase.initialize()
 #x  = camtool.getValue("x_com")
 #dx = camtool.getValue("x_rms")
 x   =  phase
-dx  =  (phase - 85)**2
+dx  =  (phase - 85) * (phase - 85)
 
 
 try: