diff --git a/core/src/com/unciv/logic/automation/Automation.kt b/core/src/com/unciv/logic/automation/Automation.kt
index f3b4987f00..89ec69260b 100644
--- a/core/src/com/unciv/logic/automation/Automation.kt
+++ b/core/src/com/unciv/logic/automation/Automation.kt
@@ -181,9 +181,9 @@ object Automation {
 
             val numberOfOurConnectedCities = findWaterConnectedCitiesAndEnemies.getReachedTiles()
                 .count { it.isCityCenter() && it.getOwner() == city.civ }
-            val numberOfOurNavalMeleeUnits = findWaterConnectedCitiesAndEnemies.getReachedTiles().asSequence()
-                .flatMap { it.getUnits() }
-                .count { isNavalMeleeUnit(it.baseUnit) }
+            val numberOfOurNavalMeleeUnits = findWaterConnectedCitiesAndEnemies.getReachedTiles()
+                .sumOf { it.getUnits().count { isNavalMeleeUnit(it.baseUnit) } }
+                
             isMissingNavalUnitsForCityDefence = numberOfOurConnectedCities > numberOfOurNavalMeleeUnits
 
             removeShips = findWaterConnectedCitiesAndEnemies.getReachedTiles().none {