diff --git a/libsanitizer/ChangeLog b/libsanitizer/ChangeLog
index 03b45e8fadd..3d790fe75d7 100644
--- a/libsanitizer/ChangeLog
+++ b/libsanitizer/ChangeLog
@@ -1,3 +1,10 @@
+2013-11-05  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR sanitizer/59018
+	* sanitizer_common/sanitizer_platform_limits_posix.cc
+	(struct_user_fpxregs_struct_sz): Initialize to 0 if __x86_64__ is
+	defined.
+
 2013-11-05  H.J. Lu  <hongjiu.lu@intel.com>
 
 	PR sanitizer/59018
diff --git a/libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.cc b/libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.cc
index 971a19314d8..b771583d064 100644
--- a/libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.cc
+++ b/libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.cc
@@ -191,7 +191,7 @@ namespace __sanitizer {
       (defined(__i386) || defined (__x86_64))  // NOLINT
   unsigned struct_user_regs_struct_sz = sizeof(struct user_regs_struct);
   unsigned struct_user_fpregs_struct_sz = sizeof(struct user_fpregs_struct);
-#if __WORDSIZE == 64
+#ifdef __x86_64
   unsigned struct_user_fpxregs_struct_sz = 0;
 #else
   unsigned struct_user_fpxregs_struct_sz = sizeof(struct user_fpxregs_struct);