Index: pregenerated/x86_64-mont-elf.S
--- pregenerated/x86_64-mont-elf.S.orig
+++ pregenerated/x86_64-mont-elf.S
@@ -1,6 +1,12 @@
 # This file is generated from a similarly-named Perl script in the BoringSSL
 # source tree. Do not edit by hand.
 
+#if defined(__CET__)
+#include <cet.h>
+#else
+#define _CET_ENDBR
+#endif
+
 #if defined(__has_feature)
 #if __has_feature(memory_sanitizer) && !defined(OPENSSL_NO_ASM)
 #define OPENSSL_NO_ASM
@@ -19,6 +25,7 @@
 .align	16
 GFp_bn_mul_mont:
 .cfi_startproc	
+	_CET_ENDBR
 	movl	%r9d,%r9d
 	movq	%rsp,%rax
 .cfi_def_cfa_register	%rax