diff --git a/Mage.Tests/src/test/java/org/mage/test/cards/abilities/keywords/HarmonizeTest.java b/Mage.Tests/src/test/java/org/mage/test/cards/abilities/keywords/HarmonizeTest.java
new file mode 100644
index 00000000000..e8f83318ab7
--- /dev/null
+++ b/Mage.Tests/src/test/java/org/mage/test/cards/abilities/keywords/HarmonizeTest.java
@@ -0,0 +1,51 @@
+package org.mage.test.cards.abilities.keywords;
+
+import mage.constants.PhaseStep;
+import mage.constants.Zone;
+import org.junit.Test;
+import org.mage.test.serverside.base.CardTestPlayerBase;
+
+/**
+ * @author TheElk801
+ */
+public class HarmonizeTest extends CardTestPlayerBase {
+
+    private static final String bear = "Grizzly Bears";
+    private static final String dragonfire = "Channeled Dragonfire";
+
+    @Test
+    public void testNoTap() {
+        addCard(Zone.BATTLEFIELD, playerA, "Mountain", 7);
+        addCard(Zone.BATTLEFIELD, playerA, bear);
+        addCard(Zone.GRAVEYARD, playerA, dragonfire);
+
+        activateAbility(1, PhaseStep.PRECOMBAT_MAIN, playerA, "Harmonize", playerB);
+        setChoice(playerA, false);
+
+        setStrictChooseMode(true);
+        setStopAt(1, PhaseStep.END_TURN);
+        execute();
+
+        assertTapped(bear, false);
+        assertLife(playerB, 20 - 2);
+    }
+
+    @Test
+    public void testTap() {
+        addCard(Zone.BATTLEFIELD, playerA, "Mountain", 5);
+        addCard(Zone.BATTLEFIELD, playerA, bear);
+        addCard(Zone.GRAVEYARD, playerA, dragonfire);
+
+        activateAbility(1, PhaseStep.PRECOMBAT_MAIN, playerA, "Harmonize", playerB);
+        setChoice(playerA, true);
+        setChoice(playerA, bear);
+        setChoice(playerA, bear);
+
+        setStrictChooseMode(true);
+        setStopAt(1, PhaseStep.END_TURN);
+        execute();
+
+        assertTapped(bear, true);
+        assertLife(playerB, 20 - 2);
+    }
+}
diff --git a/Mage/src/main/java/mage/abilities/keyword/HarmonizeAbility.java b/Mage/src/main/java/mage/abilities/keyword/HarmonizeAbility.java
index 9b4a4de7514..cb8d082be43 100644
--- a/Mage/src/main/java/mage/abilities/keyword/HarmonizeAbility.java
+++ b/Mage/src/main/java/mage/abilities/keyword/HarmonizeAbility.java
@@ -213,19 +213,30 @@ class HarmonizeCostReductionEffect extends CostModificationEffectImpl {
 
     @Override
     public boolean apply(Game game, Ability source, Ability abilityToModify) {
-        if (game.inCheckPlayableState()) {
-            return true;
-        }
         SpellAbility spellAbility = (SpellAbility) abilityToModify;
-        int power = CardUtil
-                .castStream(spellAbility.getCosts().stream(), HarmonizeCost.class)
-                .map(HarmonizeCost::getChosenCreature)
-                .map(game::getPermanent)
-                .filter(Objects::nonNull)
-                .map(MageObject::getPower)
-                .mapToInt(MageInt::getValue)
-                .map(x -> Math.max(x, 0))
-                .sum();
+        int power;
+        if (game.inCheckPlayableState()) {
+            power = game
+                    .getBattlefield()
+                    .getActivePermanents(
+                            StaticFilters.FILTER_CONTROLLED_UNTAPPED_CREATURE,
+                            source.getControllerId(), source, game
+                    ).stream()
+                    .map(MageObject::getPower)
+                    .mapToInt(MageInt::getValue)
+                    .max()
+                    .orElse(0);
+        } else {
+            power = CardUtil
+                    .castStream(spellAbility.getCosts().stream(), HarmonizeCost.class)
+                    .map(HarmonizeCost::getChosenCreature)
+                    .map(game::getPermanent)
+                    .filter(Objects::nonNull)
+                    .map(MageObject::getPower)
+                    .mapToInt(MageInt::getValue)
+                    .map(x -> Math.max(x, 0))
+                    .sum();
+        }
         if (power > 0) {
             CardUtil.adjustCost(spellAbility, power);
         }
@@ -278,12 +289,13 @@ class HarmonizeCost extends VariableCostImpl {
         Player player = game.getPlayer(source.getControllerId());
         if (player == null || !game.getBattlefield().contains(
                 StaticFilters.FILTER_CONTROLLED_UNTAPPED_CREATURE, source, game, 1
+        ) || !player.chooseUse(
+                Outcome.Benefit, "Tap an untapped creature you control for harmonize?", source, game
         )) {
             return 0;
         }
-        TargetPermanent target = new TargetPermanent(
-                0, 1, StaticFilters.FILTER_CONTROLLED_UNTAPPED_CREATURE, true
-        );
+        TargetPermanent target = new TargetPermanent(StaticFilters.FILTER_CONTROLLED_UNTAPPED_CREATURE);
+        target.withNotTarget(true);
         target.withChooseHint("for harmonize");
         player.choose(Outcome.PlayForFree, target, source, game);
         Permanent permanent = game.getPermanent(target.getFirstTarget());