diff --git a/ChangeLog b/ChangeLog
index a917b6e51e..36cd1e23e9 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,7 @@
 2011-10-13  Andreas Schwab  <schwab@redhat.com>
 
+	* sysdeps/x86_64/memrchr.S: Check for zero size.
+
 	* string/stratcliff.c: Add memrchr tests.
 
 2011-10-12  Liubov Dmitrieva  <liubov.dmitrieva@gmail.com>
diff --git a/sysdeps/x86_64/memrchr.S b/sysdeps/x86_64/memrchr.S
index 81b7a1c320..70adca379c 100644
--- a/sysdeps/x86_64/memrchr.S
+++ b/sysdeps/x86_64/memrchr.S
@@ -282,6 +282,9 @@ L(return_null):
 
 	.p2align 4
 L(length_less16_offset0):
+	test	%edx, %edx
+	jz	L(return_null)
+
 	mov	%dl, %cl
 	pcmpeqb	(%rdi), %xmm1