diff --git a/src/main/java/net/minestom/server/instance/block/BlockManager.java b/src/main/java/net/minestom/server/instance/block/BlockManager.java
index ed7c29799..fd0243002 100644
--- a/src/main/java/net/minestom/server/instance/block/BlockManager.java
+++ b/src/main/java/net/minestom/server/instance/block/BlockManager.java
@@ -12,18 +12,19 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import java.util.Map;
+import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.function.Supplier;
 
-public class BlockManager {
+public final class BlockManager {
     private final static Logger LOGGER = LoggerFactory.getLogger(BlockManager.class);
-
     // Namespace -> handler supplier
     private final Map<String, Supplier<BlockHandler>> blockHandlerMap = new ConcurrentHashMap<>();
-
     // block id -> block placement rule
     private final Int2ObjectMap<BlockPlacementRule> placementRuleMap = new Int2ObjectOpenHashMap<>();
 
+    private final Set<String> dummyWarning = ConcurrentHashMap.newKeySet(); // Prevent warning spam
+
     public void registerHandler(@NotNull String namespace, @NotNull Supplier<@NotNull BlockHandler> handlerSupplier) {
         blockHandlerMap.put(namespace, handlerSupplier);
     }
@@ -41,7 +42,11 @@ public class BlockManager {
     public @NotNull BlockHandler getHandlerOrDummy(@NotNull String namespace) {
         BlockHandler handler = getHandler(namespace);
         if (handler == null) {
-            LOGGER.warn("Block {} does not have any corresponding handler, default to dummy.", namespace);
+            if (dummyWarning.add(namespace)) {
+                LOGGER.warn("""
+                        Block {} does not have any corresponding handler, default to dummy.
+                        You may want to register a handler for this namespace to prevent any data loss.""", namespace);
+            }
             handler = BlockHandler.Dummy.get(namespace);
         }
         return handler;