diff --git a/libc/arch-arm64/generic/bionic/__memset_chk.S b/libc/arch-arm64/generic/bionic/__memset_chk.S
new file mode 100644
index 0000000..e1e29d0
--- /dev/null
+++ b/libc/arch-arm64/generic/bionic/__memset_chk.S
@@ -0,0 +1,47 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <private/bionic_asm.h>
+
+ENTRY(__memset_chk)
+  cmp x2, x3
+  // Direct b.ls memcpy may not have enough range
+  b.hi .L_memset_chk_fail
+  b memset
+
+.L_memset_chk_fail:
+  // Preserve for accurate backtrace.
+  stp x29, x30, [sp, -16]!
+  .cfi_def_cfa_offset 16
+  .cfi_rel_offset x29, 0
+  .cfi_rel_offset x30, 8
+
+  bl __memset_chk_fail
+END(__memset_chk)
+
+NOTE_GNU_PROPERTY()
diff --git a/libc/arch-arm64/generic/bionic/memset.S b/libc/arch-arm64/generic/bionic/memset.S
index 19d3510..145ae63 100644
--- a/libc/arch-arm64/generic/bionic/memset.S
+++ b/libc/arch-arm64/generic/bionic/memset.S
@@ -85,19 +85,6 @@
 
 #define L(l) .L ## l
 
-ENTRY(__memset_chk)
-  cmp count, dst
-  bls memset
-
-  // Preserve for accurate backtrace.
-  stp x29, x30, [sp, -16]!
-  .cfi_def_cfa_offset 16
-  .cfi_rel_offset x29, 0
-  .cfi_rel_offset x30, 8
-
-  bl __memset_chk_fail
-END(__memset_chk)
-
 ENTRY(memset)
 
 	dup	v0.16B, valw