diff --git a/metis_rad_cal.pro b/metis_rad_cal.pro
index 06409c0149818614b9550244e03e176d145737a4..e8d0f1561cdfcc5f12803d425681eba76d9d679c 100644
--- a/metis_rad_cal.pro
+++ b/metis_rad_cal.pro
@@ -96,6 +96,10 @@ function metis_rad_cal, data, header, cal_pack, polarimetric = polarimetric, nor
 
 	if isa(error) then error += cal_error^2
 	
+	if header.filter.contains('VL', /fold) then begin
+		history = [history, '  1 MSB = ' + string(unit_factor, format = '(E8.2)') + ' ph/cm2/s/sr']
+	endif
+
 	if header.filter.contains('UV', /fold) then begin
 	
 		; efficiency correction