diff --git a/src/main/java/ch/njol/skript/classes/data/BukkitClasses.java b/src/main/java/ch/njol/skript/classes/data/BukkitClasses.java
index ba1a419aad0..69710a1ad00 100644
--- a/src/main/java/ch/njol/skript/classes/data/BukkitClasses.java
+++ b/src/main/java/ch/njol/skript/classes/data/BukkitClasses.java
@@ -355,7 +355,7 @@ public boolean mustSyncDeserialization() {
 					protected boolean canBeInstantiated() {
 						return false;
 					}
-				}));
+				}).cloner(BlockData::clone));
 
 		Classes.registerClass(new ClassInfo<>(Location.class, "location")
 				.user("locations?")
diff --git a/src/test/java/org/skriptlang/skript/test/tests/regression/BlockDataNotCloned6829.java b/src/test/java/org/skriptlang/skript/test/tests/regression/BlockDataNotCloned6829.java
new file mode 100644
index 00000000000..b621734958d
--- /dev/null
+++ b/src/test/java/org/skriptlang/skript/test/tests/regression/BlockDataNotCloned6829.java
@@ -0,0 +1,53 @@
+/**
+ *   This file is part of Skript.
+ *
+ *  Skript is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  Skript is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with Skript.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Copyright Peter Güttinger, SkriptLang team and contributors
+ */
+package org.skriptlang.skript.test.tests.regression;
+
+import ch.njol.skript.lang.Effect;
+import ch.njol.skript.lang.TriggerItem;
+import ch.njol.skript.lang.util.ContextlessEvent;
+import ch.njol.skript.test.runner.SkriptJUnitTest;
+import ch.njol.skript.variables.Variables;
+import org.bukkit.block.data.type.Tripwire;
+import org.bukkit.event.Event;
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.util.Objects;
+
+public class BlockDataNotCloned6829 extends SkriptJUnitTest {
+
+	public void run(String unparsedEffect, Event event) {
+		Effect effect = Effect.parse(unparsedEffect, "Can't understand this effect: " + unparsedEffect);
+		if (effect == null)
+			throw new IllegalStateException();
+		TriggerItem.walk(effect, event);
+	}
+
+	@Test
+	public void test() {
+		Event event = ContextlessEvent.get();
+		run("set {_original tripwire} to tripwire[]", event);
+		run("set {_another tripwire} to {_original tripwire}", event);
+		Tripwire originalTripwire = (Tripwire) Objects.requireNonNull(Variables.getVariable("original tripwire", event, true));
+		Tripwire anotherTripwire = (Tripwire) Objects.requireNonNull(Variables.getVariable("another tripwire", event, true));
+		anotherTripwire.setDisarmed(true);
+		Assert.assertFalse(originalTripwire.isDisarmed());
+	}
+
+}