diff --git a/forge-ai/src/main/java/forge/ai/ability/TapAiBase.java b/forge-ai/src/main/java/forge/ai/ability/TapAiBase.java
index a8f46f2a180..95efebb90c8 100644
--- a/forge-ai/src/main/java/forge/ai/ability/TapAiBase.java
+++ b/forge-ai/src/main/java/forge/ai/ability/TapAiBase.java
@@ -11,6 +11,7 @@ import forge.ai.ComputerUtilAbility;
 import forge.ai.ComputerUtilCard;
 import forge.ai.SpellAbilityAi;
 import forge.game.Game;
+import forge.game.ability.AbilityUtils;
 import forge.game.ability.ApiType;
 import forge.game.card.Card;
 import forge.game.card.CardCollection;
@@ -309,9 +310,8 @@ public abstract class TapAiBase extends SpellAbilityAi {
                 return true;
             }
 
-            // TODO: use Defined to determine, if this is an unfavorable result
-
-            return true;
+            final List<Card> pDefined = AbilityUtils.getDefinedCards(sa.getHostCard(), sa.getParam("Defined"), sa);
+            return pDefined.isEmpty() || (pDefined.get(0).isUntapped() && pDefined.get(0).getController() != ai);
         } else {
             sa.resetTargets();
             if (tapPrefTargeting(ai, source, sa, mandatory)) {
diff --git a/forge-ai/src/main/java/forge/ai/ability/UntapAi.java b/forge-ai/src/main/java/forge/ai/ability/UntapAi.java
index 47c443f59b8..8816b0a5506 100644
--- a/forge-ai/src/main/java/forge/ai/ability/UntapAi.java
+++ b/forge-ai/src/main/java/forge/ai/ability/UntapAi.java
@@ -66,7 +66,7 @@ public class UntapAi extends SpellAbilityAi {
 
         if (!sa.usesTargeting()) {
             final List<Card> pDefined = AbilityUtils.getDefinedCards(source, sa.getParam("Defined"), sa);
-            return pDefined == null || !pDefined.get(0).isUntapped() || pDefined.get(0).getController() != ai;
+            return pDefined.isEmpty() || (pDefined.get(0).isTapped() && pDefined.get(0).getController() == ai);
         } else {
             return untapPrefTargeting(ai, sa, false);
         }
@@ -82,9 +82,8 @@ public class UntapAi extends SpellAbilityAi {
                 return false;
             }
 
-            // TODO: use Defined to determine, if this is an unfavorable result
             final List<Card> pDefined = AbilityUtils.getDefinedCards(sa.getHostCard(), sa.getParam("Defined"), sa);
-            return pDefined == null || !pDefined.get(0).isUntapped() || pDefined.get(0).getController() != ai;
+            return pDefined.isEmpty() || (pDefined.get(0).isTapped() && pDefined.get(0).getController() == ai);
         } else {
             if (untapPrefTargeting(ai, sa, mandatory)) {
                 return true;