diff --git a/libc/include/setjmp.h b/libc/include/setjmp.h
index c2a9544..a3de9c7 100644
--- a/libc/include/setjmp.h
+++ b/libc/include/setjmp.h
@@ -52,6 +52,8 @@
 #define _JBLEN 64
 #elif defined(__i386__)
 #define _JBLEN 10
+#elif defined(__riscv)
+#define _JBLEN 29
 #elif defined(__x86_64__)
 #define _JBLEN 11
 #endif