diff --git a/runtime/rpc_server.cpp b/runtime/rpc_server.cpp
index 1dc4eaa..c720470 100644
--- a/runtime/rpc_server.cpp
+++ b/runtime/rpc_server.cpp
@@ -23,6 +23,7 @@ auto sliger::rpc::BufferedWriter::write(uint8_t byte) -> Res<Unit>
         }
     }
     this->buffer[this->occupied] = byte;
+    this->occupied += 1;
     return Unit {};
 }