diff --git a/lignumis/prototypes/compatibility/any-planet-start.lua b/lignumis/prototypes/compatibility/any-planet-start.lua
index f72a020..9022b8e 100644
--- a/lignumis/prototypes/compatibility/any-planet-start.lua
+++ b/lignumis/prototypes/compatibility/any-planet-start.lua
@@ -23,7 +23,7 @@ Technology:new("planet-discovery-" .. target_planet)
             time = 30
         }
     })
-    :addPrerequisite("provisional-rocketry")
+    :setPrerequisites({ "provisional-rocketry" })
 Technology:new("iron-processing"):replacePrerequisite("planet-discovery-nauvis", "planet-discovery-" .. target_planet)
 Technology:new("copper-processing"):replacePrerequisite("planet-discovery-nauvis", "planet-discovery-" .. target_planet)