diff --git a/libc/kernel/uapi/linux/prctl.h b/libc/kernel/uapi/linux/prctl.h
index 5031e8d..9015e29 100644
--- a/libc/kernel/uapi/linux/prctl.h
+++ b/libc/kernel/uapi/linux/prctl.h
@@ -143,6 +143,7 @@
 #define PR_SPEC_ENABLE (1UL << 1)
 #define PR_SPEC_DISABLE (1UL << 2)
 #define PR_SPEC_FORCE_DISABLE (1UL << 3)
+#define PR_SPEC_DISABLE_NOEXEC (1UL << 4)
 #define PR_PAC_RESET_KEYS 54
 #define PR_PAC_APIAKEY (1UL << 0)
 #define PR_PAC_APIBKEY (1UL << 1)