diff --git a/src/main/java/forge/card/cost/CostTapType.java b/src/main/java/forge/card/cost/CostTapType.java
index 594dc6b8789..0fe89c4dc98 100644
--- a/src/main/java/forge/card/cost/CostTapType.java
+++ b/src/main/java/forge/card/cost/CostTapType.java
@@ -165,9 +165,18 @@ public class CostTapType extends CostPartWithList {
     @Override
     public final boolean decideAIPayment(final SpellAbility ability, final Card source, final CostPayment payment) {
         final boolean tap = payment.getCost().getTap();
-        final Integer c = this.convertAmount();
+        final String amount = this.getAmount();
+        Integer c = this.convertAmount();
         if (c == null) {
-            // Determine Amount
+            final String sVar = source.getSVar(amount);
+            if (sVar.equals("XChoice")) {
+                CardList typeList = ability.getActivatingPlayer().getCardsIn(Zone.Battlefield);
+                typeList = typeList.getValidCards(this.getType().split(";"), ability.getActivatingPlayer(),
+                        ability.getSourceCard());
+                typeList = typeList.filter(CardListFilter.UNTAPPED);
+                c = typeList.size();
+                source.setSVar("ChosenX", "Number$" + Integer.toString(c));
+            }
         }
 
         this.setList(ComputerUtil.chooseTapType(this.getType(), source, tap, c));