diff --git a/src/drivers/linux_gpio/linux_gpio.cpp b/src/drivers/linux_gpio/linux_gpio.cpp
index 674b445514..4053c87f2f 100644
--- a/src/drivers/linux_gpio/linux_gpio.cpp
+++ b/src/drivers/linux_gpio/linux_gpio.cpp
@@ -205,7 +205,7 @@ int LinuxGPIO::_readValue(int pin)
 
 	ret = 0;
 
-	ret = strtol(buf, NULL, 10);
+	ret = strtol(buf, nullptr, 10);
 
 cleanup:
 	close(fd);