diff --git a/core/src/com/unciv/logic/civilization/CivilizationInfo.kt b/core/src/com/unciv/logic/civilization/CivilizationInfo.kt
index 4f1cf567..3cac2b5e 100644
--- a/core/src/com/unciv/logic/civilization/CivilizationInfo.kt
+++ b/core/src/com/unciv/logic/civilization/CivilizationInfo.kt
@@ -426,6 +426,8 @@ class CivilizationInfo {
 
     fun canEnterTiles(otherCiv: CivilizationInfo): Boolean {
         if(otherCiv==this) return true
+        if(!diplomacy.containsKey(otherCiv.civName)) // not encountered yet
+            return false
         if(isAtWarWith(otherCiv)) return true
         if(getDiplomacyManager(otherCiv).hasOpenBorders) return true
         return false