diff -urN a/mfbt/double-conversion/utils.h b/mfbt/double-conversion/utils.h
--- a/mfbt/double-conversion/utils.h	2013-10-29 14:40:19.000000000 -0600
+++ b/mfbt/double-conversion/utils.h	2015-07-10 22:55:40.262596161 -0600
@@ -58,7 +58,8 @@
     defined(__mips__) || defined(__powerpc__) || \
     defined(__sparc__) || defined(__sparc) || defined(__s390__) || \
     defined(__SH4__) || defined(__alpha__) || \
-    defined(_MIPS_ARCH_MIPS32R2)
+    defined(_MIPS_ARCH_MIPS32R2) || \
+    defined(__AARCH64EL__)
 #define DOUBLE_CONVERSION_CORRECT_DOUBLE_OPERATIONS 1
 #elif defined(_M_IX86) || defined(__i386__) || defined(__i386)
 #if defined(_WIN32)