diff --git a/buffer/src/main/kotlin/org/openrs2/buffer/ByteBufBodyHandler.kt b/buffer/src/main/kotlin/org/openrs2/buffer/ByteBufBodyHandler.kt
index de77a22e..c57e2650 100644
--- a/buffer/src/main/kotlin/org/openrs2/buffer/ByteBufBodyHandler.kt
+++ b/buffer/src/main/kotlin/org/openrs2/buffer/ByteBufBodyHandler.kt
@@ -24,7 +24,7 @@ public class ByteBufBodyHandler @Inject constructor(
                 subscription.request(Long.MAX_VALUE)
             }
 
-            override fun onNext(item: MutableList<ByteBuffer>) {
+            override fun onNext(item: List<ByteBuffer>) {
                 for (b in item) {
                     buf.addComponent(Unpooled.wrappedBuffer(b))
                 }