diff --git a/AI/BattleAI/BattleExchangeVariant.cpp b/AI/BattleAI/BattleExchangeVariant.cpp
index 8ae233e41..6a274152a 100644
--- a/AI/BattleAI/BattleExchangeVariant.cpp
+++ b/AI/BattleAI/BattleExchangeVariant.cpp
@@ -327,7 +327,7 @@ MoveTarget BattleExchangeEvaluator::findMoveTowardsUnreachable(
 	return result;
 }
 
-std::vector<const battle::Unit *> BattleExchangeEvaluator::getAdjacentUnits(const battle::Unit * blockerUnit)
+std::vector<const battle::Unit *> BattleExchangeEvaluator::getAdjacentUnits(const battle::Unit * blockerUnit) const
 {
 	std::queue<const battle::Unit *> queue;
 	std::vector<const battle::Unit *> checkedStacks;
diff --git a/AI/BattleAI/BattleExchangeVariant.h b/AI/BattleAI/BattleExchangeVariant.h
index 36b8b2592..e71f2785d 100644
--- a/AI/BattleAI/BattleExchangeVariant.h
+++ b/AI/BattleAI/BattleExchangeVariant.h
@@ -129,7 +129,7 @@ public:
 		DamageCache & damageCache,
 		std::shared_ptr<HypotheticBattle> hb);
 
-	std::vector<const battle::Unit *> getAdjacentUnits(const battle::Unit * unit);
+	std::vector<const battle::Unit *> getAdjacentUnits(const battle::Unit * unit) const;
 
 	float getPositiveEffectMultiplier() { return 1; }
 	float getNegativeEffectMultiplier() { return negativeEffectMultiplier; }