diff --git a/libc/arch-x86_64/string/sse2-memset-slm.S b/libc/arch-x86_64/string/sse2-memset-slm.S
index bfcafae..15253da 100644
--- a/libc/arch-x86_64/string/sse2-memset-slm.S
+++ b/libc/arch-x86_64/string/sse2-memset-slm.S
@@ -28,11 +28,9 @@
 SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
 
-#include "cache.h"
+#include <private/bionic_asm.h>
 
-#ifndef MEMSET
-# define MEMSET		memset
-#endif
+#include "cache.h"
 
 #ifndef L
 # define L(label)	.L##label
@@ -42,30 +40,19 @@
 # define ALIGN(n)	.p2align n
 #endif
 
-#ifndef cfi_startproc
-# define cfi_startproc			.cfi_startproc
-#endif
 
-#ifndef cfi_endproc
-# define cfi_endproc			.cfi_endproc
-#endif
+ENTRY(__memset_chk)
+  # %rdi = dst, %rsi = byte, %rdx = n, %rcx = dst_len
+  cmp %rdx, %rcx
+  jl memset
 
-#ifndef ENTRY
-# define ENTRY(name)			\
-	.type name,  @function;	\
-	.globl name;			\
-name:					\
-	cfi_startproc
-#endif
+  # TODO: include __memset_chk_fail in the backtrace?
+  call PIC_PLT(__memset_chk_fail)
+END(__memset_chk)
 
-#ifndef END
-# define END(name)			\
-	cfi_endproc;			\
-	.size name, .-name
-#endif
 
 	.section .text.sse2,"ax",@progbits
-ENTRY (MEMSET)
+ENTRY(memset)
 	movq	%rdi, %rax
 #ifdef USE_AS_BZERO_P
 	mov	%rsi, %rdx
@@ -170,4 +157,4 @@
 	sfence
 	ret
 
-END (MEMSET)
+END(memset)
diff --git a/libc/bionic/fortify.cpp b/libc/bionic/fortify.cpp
index a1db2a4..ccbdec0 100644
--- a/libc/bionic/fortify.cpp
+++ b/libc/bionic/fortify.cpp
@@ -153,7 +153,7 @@
   return memrchr(s, c, n);
 }
 
-#if !defined(__aarch64__) && !defined(__arm__) // TODO: add optimized assembler for the others too.
+#if !defined(__aarch64__) && !defined(__arm__) && !defined(__x86_64__) // TODO: add optimized assembler for the others too.
 // Runtime implementation of __builtin___memset_chk (used directly by compiler, not in headers).
 extern "C" void* __memset_chk(void* dst, int byte, size_t count, size_t dst_len) {
   __check_count("memset", "count", count);