diff --git a/arch/arm/src/am335x/am335x_serial.c b/arch/arm/src/am335x/am335x_serial.c
index 9ee0e66671..ba1e3eddcf 100644
--- a/arch/arm/src/am335x/am335x_serial.c
+++ b/arch/arm/src/am335x/am335x_serial.c
@@ -64,6 +64,7 @@
 #include "chip.h"
 #include "hardware/am335x_uart.h"
 #include "am335x_gpio.h"
+#include "am335x_pinmux.h"
 #include "am335x_serial.h"
 
 /****************************************************************************