diff --git a/core/src/com/unciv/logic/BackwardCompatibility.kt b/core/src/com/unciv/logic/BackwardCompatibility.kt
index 792bd3a3a4..b85b4a51e7 100644
--- a/core/src/com/unciv/logic/BackwardCompatibility.kt
+++ b/core/src/com/unciv/logic/BackwardCompatibility.kt
@@ -128,6 +128,11 @@ object BackwardCompatibility {
             for (tech in civInfo.tech.techsResearched.toList())
                 if (!ruleset.technologies.containsKey(tech))
                     civInfo.tech.techsResearched.remove(tech)
+            
+            for (tech in civInfo.tech.techsToResearch.toList())
+                if (!ruleset.technologies.containsKey(tech))
+                    civInfo.tech.techsToResearch.remove(tech)
+            
             for (policy in civInfo.policies.adoptedPolicies.toList())
                 if (!ruleset.policies.containsKey(policy))
                     civInfo.policies.adoptedPolicies.remove(policy)