diff --git a/arch/risc-v/src/c906/c906_timerisr.c b/arch/risc-v/src/c906/c906_timerisr.c
index 843f9790b9..81905a033d 100644
--- a/arch/risc-v/src/c906/c906_timerisr.c
+++ b/arch/risc-v/src/c906/c906_timerisr.c
@@ -24,6 +24,7 @@
 
 #include <nuttx/config.h>
 
+#include <assert.h>
 #include <stdint.h>
 #include <time.h>
 #include <debug.h>