diff --git a/forge-game/src/main/java/forge/game/combat/CombatUtil.java b/forge-game/src/main/java/forge/game/combat/CombatUtil.java
index ce67da462ad..4ad747177a2 100644
--- a/forge-game/src/main/java/forge/game/combat/CombatUtil.java
+++ b/forge-game/src/main/java/forge/game/combat/CombatUtil.java
@@ -346,9 +346,9 @@ public class CombatUtil {
         return attackCost;
     }
 
-    public static CardCollection getOptionAttackCostCreatures(final Player attacker) {
+    public static CardCollection getOptionalAttackCostCreatures(final CardCollection attackers) {
         final CardCollection exerters = new CardCollection();
-        for (final Card card : attacker.getCardsIn(ZoneType.STATIC_ABILITIES_SOURCE_ZONES)) {
+        for (final Card card : attackers) {
             for (final StaticAbility stAb : card.getStaticAbilities()) {
                 if (stAb.hasExertCost(card)) {
                     exerters.add(card);
diff --git a/forge-game/src/main/java/forge/game/phase/PhaseHandler.java b/forge-game/src/main/java/forge/game/phase/PhaseHandler.java
index eacb80f80a3..f6b7caccb9d 100644
--- a/forge-game/src/main/java/forge/game/phase/PhaseHandler.java
+++ b/forge-game/src/main/java/forge/game/phase/PhaseHandler.java
@@ -559,8 +559,8 @@ public class PhaseHandler implements java.io.Serializable {
                     }
                 }
 
-                // Exert creatures here
-                List<Card> possibleExerters = CombatUtil.getOptionAttackCostCreatures(whoDeclares);
+                // CR 508.1g
+                List<Card> possibleExerters = CombatUtil.getOptionalAttackCostCreatures(combat.getAttackers());
                 if (!possibleExerters.isEmpty()) {
                     possibleExerters = whoDeclares.getController().exertAttackers(possibleExerters);
                 }
diff --git a/forge-game/src/main/java/forge/game/staticability/StaticAbility.java b/forge-game/src/main/java/forge/game/staticability/StaticAbility.java
index f4d04647c98..f02e1bad2ef 100644
--- a/forge-game/src/main/java/forge/game/staticability/StaticAbility.java
+++ b/forge-game/src/main/java/forge/game/staticability/StaticAbility.java
@@ -39,6 +39,7 @@ import forge.game.card.CardCollectionView;
 import forge.game.card.CardLists;
 import forge.game.card.CardState;
 import forge.game.cost.Cost;
+import forge.game.cost.CostExert;
 import forge.game.phase.PhaseHandler;
 import forge.game.phase.PhaseType;
 import forge.game.player.Player;
@@ -337,7 +338,7 @@ public class StaticAbility extends CardTraitBase implements IIdentifiable, Clone
         if (this.isSuppressed() || !getParam("Mode").equals("OptionalAttackCost") || !this.checkConditions()) {
             return false;
         }
-        return StaticAbilityCantAttackBlock.getAttackCost(this, attacker, null) != null;
+        return StaticAbilityCantAttackBlock.getAttackCost(this, attacker, null).hasSpecificCostType(CostExert.class);
     }
 
     public final Cost getBlockCost(final Card blocker, final Card attacker) {