diff --git a/src/main/java/io/lettuce/core/RedisCommandBuilder.java b/src/main/java/io/lettuce/core/RedisCommandBuilder.java
index ad6b7bb670..dc4d5ae08c 100644
--- a/src/main/java/io/lettuce/core/RedisCommandBuilder.java
+++ b/src/main/java/io/lettuce/core/RedisCommandBuilder.java
@@ -1728,7 +1728,7 @@ Command<K, V, String> ltrim(K key, long start, long stop) {
     }
 
     Command<K, V, Long> memoryUsage(K key) {
-        return createCommand(MEMORY, new IntegerOutput<>(codec), new CommandArgs<>(codec).add(USAGE).add(key.toString()));
+        return createCommand(MEMORY, new IntegerOutput<>(codec), new CommandArgs<>(codec).add(USAGE).addKey(key));
     }
 
     Command<K, V, List<V>> mget(K... keys) {