diff --git a/apps/scout_monitor/src/ncolors.cpp b/apps/scout_monitor/src/ncolors.cpp
index a3ea543..2d76168 100644
--- a/apps/scout_monitor/src/ncolors.cpp
+++ b/apps/scout_monitor/src/ncolors.cpp
@@ -54,6 +54,8 @@ short CursorColor(int fg)
         return (COLOR_YELLOW);
     case 7: /* 111 */
         return (COLOR_WHITE);
+    default:
+        return COLOR_BLACK;
     }
 }
 } // namespace
diff --git a/include/wrp_sdk/asyncio/async_serial.hpp b/include/wrp_sdk/asyncio/async_serial.hpp
index 4c7e473..3dea233 100644
--- a/include/wrp_sdk/asyncio/async_serial.hpp
+++ b/include/wrp_sdk/asyncio/async_serial.hpp
@@ -23,7 +23,7 @@ class AsyncSerial : public AsyncListener,
                     public std::enable_shared_from_this<AsyncSerial> {
  public:
   using ReceiveCallback =
-      std::function<void(uint8_t *data, size_t len, const size_t bufsize)>;
+      std::function<void(uint8_t *data, const size_t bufsize, size_t len)>;
 
  public:
   AsyncSerial(std::string port_name, uint32_t baud_rate = 115200);
@@ -56,7 +56,7 @@ class AsyncSerial : public AsyncListener,
   bool tx_in_progress_ = false;
 
   bool SetupPort();
-  void DefaultReceiveCallback(uint8_t *data, size_t len, const size_t bufsize);
+  void DefaultReceiveCallback(uint8_t *data, const size_t bufsize, size_t len);
   void ReadFromPort();
   void WriteToPort(bool check_if_busy);
 };
diff --git a/src/asyncio/async_serial.cpp b/src/asyncio/async_serial.cpp
index 21104b6..1775f03 100644
--- a/src/asyncio/async_serial.cpp
+++ b/src/asyncio/async_serial.cpp
@@ -80,8 +80,8 @@ void AsyncSerial::StopService() {
   port_opened_ = false;
 }
 
-void AsyncSerial::DefaultReceiveCallback(uint8_t *data, size_t len,
-                                         const size_t bufsize) {}
+void AsyncSerial::DefaultReceiveCallback(uint8_t *data, const size_t bufsize,
+                                         size_t len) {}
 
 void AsyncSerial::ReadFromPort() {
   auto sthis = shared_from_this();
@@ -93,9 +93,13 @@ void AsyncSerial::ReadFromPort() {
           return;
         }
 
-        if (sthis->rcv_cb_ != nullptr)
-          sthis->rcv_cb_(sthis->rx_buf_.data(), bytes_transferred,
-                         sthis->rx_buf_.size());
+        if (sthis->rcv_cb_ != nullptr) {
+          sthis->rcv_cb_(sthis->rx_buf_.data(), sthis->rx_buf_.size(),
+                         bytes_transferred);
+        } else {
+          sthis->DefaultReceiveCallback(
+              sthis->rx_buf_.data(), sthis->rx_buf_.size(), bytes_transferred);
+        }
         sthis->ReadFromPort();
       });
 }