diff --git a/core/components/uart/uart.cpp b/core/components/uart/uart.cpp
index b5f0b80..77c1050 100644
--- a/core/components/uart/uart.cpp
+++ b/core/components/uart/uart.cpp
@@ -207,6 +207,7 @@ int Uart::receive(char *data, int size_max) {
       logger->debug("{} receive: {}[{}]", this->device.name, StringUtil().bytesToString((const uint8_t *)data, ret));
     }
   }
+  return ret;
 }
 int Uart::stop() {
   int rc = uartStop(&this->device);