diff --git a/Script/DCS extensions/UnitCallsignMaker.lua b/Script/DCS extensions/UnitCallsignMaker.lua
index d2c5e7d..e222b51 100644
--- a/Script/DCS extensions/UnitCallsignMaker.lua	
+++ b/Script/DCS extensions/UnitCallsignMaker.lua	
@@ -229,7 +229,7 @@ do
         for _,g in ipairs(missionGroups) do
             if g.units and g.units[1] then
                 local unit = g.units[1]
-                if unit.callsign and unit.callsign[1] and unit.callsign.name then
+                if unit.callsign and type(unit.callsign) == "table" and unit.callsign.name then
                     local callsignName = unit.callsign.name:sub(1, #unit.callsign.name - 2)
                     incrementCallsign(callsignName, unit.callsign[2])
                 end