diff --git a/PHI-CL/control.lua b/PHI-CL/control.lua
index 4dd17d2..bf1ee39 100644
--- a/PHI-CL/control.lua
+++ b/PHI-CL/control.lua
@@ -388,7 +388,7 @@ local function handle_research_queue(entity, combinator)
         end
 
         for _, ss in pairs(s) do
-            if ss.signal and ss.signal.type == 'virtual' and ss.count > 0 then
+            if ss.signal and ss.signal.type == 'virtual' and ss.signal.quality == 'normal' and ss.count > 0 then
                 local tn = ss.signal.name:gsub('signal-', '')
 
                 if game.forces.player.technologies[tn] and game.forces.player.technologies[tn].enabled and game.forces.player.technologies[tn].research_unit_count_formula then