diff --git a/Source/WTF/wtf/Platform.h b/Source/WTF/wtf/Platform.h
index 3f6f2bd..fd253f5 100644
--- a/Source/WTF/wtf/Platform.h
+++ b/Source/WTF/wtf/Platform.h
@@ -314,7 +314,12 @@
 
 #endif /* ARM */
 
-#if CPU(ARM) || CPU(MIPS) || CPU(SH4) || CPU(SPARC)
+/* CPU(AARCH64) - Aarch64 */
+#if defined(__aarch64__)
+#define WTF_CPU_AARCH64 1
+#endif
+
+#if CPU(ARM) || CPU(MIPS) || CPU(SH4) || CPU(SPARC) || CPU(AARCH64)
 #define WTF_CPU_NEEDS_ALIGNED_ACCESS 1
 #endif
 
@@ -744,7 +749,8 @@
     || CPU(ALPHA) \
     || CPU(SPARC64) \
     || CPU(S390X) \
-    || CPU(PPC64)
+    || CPU(PPC64) \
+    || CPU(AARCH64)
 #define WTF_USE_JSVALUE64 1
 #else
 #define WTF_USE_JSVALUE32_64 1
diff --git a/Source/WTF/wtf/dtoa/utils.h b/Source/WTF/wtf/dtoa/utils.h
index ab8f251..d6a99f2 100644
--- a/Source/WTF/wtf/dtoa/utils.h
+++ b/Source/WTF/wtf/dtoa/utils.h
@@ -49,7 +49,7 @@
 defined(__ARMEL__) || \
 defined(_MIPS_ARCH_MIPS32R2)
 #define DOUBLE_CONVERSION_CORRECT_DOUBLE_OPERATIONS 1
-#elif CPU(MIPS) || CPU(PPC) || CPU(PPC64) || OS(WINCE) || CPU(SH4) || CPU(S390) || CPU(S390X) || CPU(IA64) || CPU(SPARC) || CPU(ALPHA)
+#elif CPU(MIPS) || CPU(PPC) || CPU(PPC64) || OS(WINCE) || CPU(SH4) || CPU(S390) || CPU(S390X) || CPU(IA64) || CPU(SPARC) || CPU(ALPHA) || CPU(AARCH64)
 #define DOUBLE_CONVERSION_CORRECT_DOUBLE_OPERATIONS 1
 #elif defined(_M_IX86) || defined(__i386__)
 #if defined(_WIN32)