diff --git a/fabric-registry-sync-v0/src/client/java/net/fabricmc/fabric/impl/client/registry/sync/ClientRegistrySyncHandler.java b/fabric-registry-sync-v0/src/client/java/net/fabricmc/fabric/impl/client/registry/sync/ClientRegistrySyncHandler.java
index 3a172cd2fe..d821a8dee5 100644
--- a/fabric-registry-sync-v0/src/client/java/net/fabricmc/fabric/impl/client/registry/sync/ClientRegistrySyncHandler.java
+++ b/fabric-registry-sync-v0/src/client/java/net/fabricmc/fabric/impl/client/registry/sync/ClientRegistrySyncHandler.java
@@ -103,12 +103,11 @@ public static void apply(RegistryPacketHandler.SyncedPacketData data) throws Rem
 				}
 			}
 
-			if (registry instanceof RemappableRegistry remappableRegistry) {
-				remappableRegistry.remap(entry.getValue(), RemappableRegistry.RemapMode.REMOTE);
-				return;
+			if (!(registry instanceof RemappableRegistry remappableRegistry)) {
+				throw new RemapException("Registry " + registryId + " is not remappable");
 			}
 
-			throw new RemapException("Registry " + registryId + " is not remappable");
+			remappableRegistry.remap(entry.getValue(), RemappableRegistry.RemapMode.REMOTE);
 		}
 	}
 
diff --git a/fabric-registry-sync-v0/src/test/java/net/fabricmc/fabric/test/registry/sync/RegistryRemapTest.java b/fabric-registry-sync-v0/src/test/java/net/fabricmc/fabric/test/registry/sync/RegistryRemapTest.java
index 0e5180d401..62511051e1 100644
--- a/fabric-registry-sync-v0/src/test/java/net/fabricmc/fabric/test/registry/sync/RegistryRemapTest.java
+++ b/fabric-registry-sync-v0/src/test/java/net/fabricmc/fabric/test/registry/sync/RegistryRemapTest.java
@@ -22,6 +22,7 @@
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import java.util.ArrayList;
+import java.util.EnumSet;
 import java.util.List;
 import java.util.Map;
 import java.util.UUID;
@@ -53,6 +54,7 @@
 import net.fabricmc.fabric.impl.registry.sync.RemapException;
 import net.fabricmc.fabric.impl.registry.sync.RemappableRegistry;
 import net.fabricmc.fabric.impl.registry.sync.packet.DirectRegistryPacketHandler;
+import net.fabricmc.fabric.impl.registry.sync.packet.RegistryPacketHandler;
 
 public class RegistryRemapTest {
 	private RegistryKey<Registry<String>> testRegistryKey;
@@ -248,6 +250,71 @@ void missingRemoteEntries() throws RemapException {
 		assertEquals(2, testRegistry.getRawId("two"));
 	}
 
+	@Test
+	void remapRegistryFromPacketData() throws RemapException {
+		RemappableRegistry remappableRegistry = (RemappableRegistry) testRegistry;
+
+		assertEquals(0, testRegistry.getRawId("zero"));
+		assertEquals(1, testRegistry.getRawId("one"));
+		assertEquals(2, testRegistry.getRawId("two"));
+
+		ClientRegistrySyncHandler.apply(new RegistryPacketHandler.SyncedPacketData(
+				Map.of(
+					testRegistryKey.getValue(), asFastMap(Map.of(
+						id("zero"), 2,
+						id("one"), 1,
+						id("two"), 0
+					))
+				),
+				Map.of()
+		));
+
+		assertEquals(2, testRegistry.getRawId("zero"));
+		assertEquals(1, testRegistry.getRawId("one"));
+		assertEquals(0, testRegistry.getRawId("two"));
+
+		remappableRegistry.unmap();
+
+		assertEquals(0, testRegistry.getRawId("zero"));
+		assertEquals(1, testRegistry.getRawId("one"));
+		assertEquals(2, testRegistry.getRawId("two"));
+	}
+
+	@Test
+	void remapRegistryFromPacketDataIgnoreOptional() throws RemapException {
+		RemappableRegistry remappableRegistry = (RemappableRegistry) testRegistry;
+
+		assertEquals(0, testRegistry.getRawId("zero"));
+		assertEquals(1, testRegistry.getRawId("one"));
+		assertEquals(2, testRegistry.getRawId("two"));
+
+		ClientRegistrySyncHandler.apply(new RegistryPacketHandler.SyncedPacketData(
+				Map.of(
+					testRegistryKey.getValue(), asFastMap(Map.of(
+							id("zero"), 2,
+							id("one"), 1,
+							id("two"), 0
+					)),
+					Identifier.of("test", "optional"), asFastMap(Map.of(
+						id("test"), 0
+					))
+				),
+				Map.of(
+						Identifier.of("test", "optional"), EnumSet.of(RegistryAttribute.OPTIONAL)
+				)
+		));
+
+		assertEquals(2, testRegistry.getRawId("zero"));
+		assertEquals(1, testRegistry.getRawId("one"));
+		assertEquals(0, testRegistry.getRawId("two"));
+
+		remappableRegistry.unmap();
+
+		assertEquals(0, testRegistry.getRawId("zero"));
+		assertEquals(1, testRegistry.getRawId("one"));
+		assertEquals(2, testRegistry.getRawId("two"));
+	}
+
 	private static List<Boolean> receivePayloads(List<DirectRegistryPacketHandler.Payload> payloads) throws RemapException {
 		var results = new ArrayList<Boolean>();