diff --git a/libc/arch-riscv64/string/memset_chk.c b/libc/arch-riscv64/string/memset_chk.c
new file mode 100644
index 0000000..bdd15a5
--- /dev/null
+++ b/libc/arch-riscv64/string/memset_chk.c
@@ -0,0 +1,9 @@
+#include <stdint.h>
+
+extern void* memset(void*, int, size_t);
+extern void* __memset_chk_fail(void*, int, size_t, size_t);
+
+void* __memset_chk(void* dst, int c, size_t n, size_t dst_len) {
+  if (dst_len < n) __memset_chk_fail(dst, c, n, dst_len);
+  return memset(dst, c, n);
+}