diff --git a/arch/risc-v/src/litex/litex_serial.c b/arch/risc-v/src/litex/litex_serial.c
index 919ed9faa9..0c8f4024c8 100644
--- a/arch/risc-v/src/litex/litex_serial.c
+++ b/arch/risc-v/src/litex/litex_serial.c
@@ -36,6 +36,7 @@
 #include <nuttx/irq.h>
 #include <nuttx/arch.h>
 #include <nuttx/serial/serial.h>
+#include <nuttx/spinlock.h>
 
 #include <arch/board/board.h>