diff --git a/js/src/assembler/jit/ExecutableAllocator.h b/js/src/assembler/jit/ExecutableAllocator.h
index c071c33..90764c3 100644
--- a/js/src/assembler/jit/ExecutableAllocator.h
+++ b/js/src/assembler/jit/ExecutableAllocator.h
@@ -382,6 +382,12 @@ public:
     {
         reprotectRegion(start, size, Executable);
     }
+#elif WTF_CPU_AARCH64 && WTF_PLATFORM_LINUX
+    static void cacheFlush(void* code, size_t size)
+    {
+        intptr_t end = reinterpret_cast<intptr_t>(code) + size;
+        __builtin___clear_cache(reinterpret_cast<char*>(code), reinterpret_cast<char*>(end));
+    }
 #else
     static void makeWritable(void*, size_t) {}
     static void makeExecutable(void*, size_t) {}
diff --git a/js/src/assembler/wtf/Platform.h b/js/src/assembler/wtf/Platform.h
index 0c84896..e8763a7 100644
--- a/js/src/assembler/wtf/Platform.h
+++ b/js/src/assembler/wtf/Platform.h
@@ -325,6 +325,10 @@
 #define WTF_THUMB_ARCH_VERSION 0
 #endif
 
+/* CPU(AArch64) - 64-bit ARM */
+#if defined(__aarch64__)
+#define WTF_CPU_AARCH64 1
+#endif
 
 /* WTF_CPU_ARMV5_OR_LOWER - ARM instruction set v5 or earlier */
 /* On ARMv5 and below the natural alignment is required. 
diff --git a/js/src/configure.in b/js/src/configure.in
index 15605b2..19fd704 100644
--- a/js/src/configure.in
+++ b/js/src/configure.in
@@ -1121,6 +1121,10 @@ arm*)
     CPU_ARCH=arm
     ;;
 
+aarch64)
+    CPU_ARCH=aarch64
+    ;;
+
 mips|mipsel)
     CPU_ARCH="mips"
     ;;
diff --git a/mfbt/double-conversion/utils.h b/mfbt/double-conversion/utils.h
index 0eec2d9..fe26dab 100644
--- a/mfbt/double-conversion/utils.h
+++ b/mfbt/double-conversion/utils.h
@@ -58,6 +58,7 @@
     defined(__mips__) || defined(__powerpc__) || \
     defined(__sparc__) || defined(__sparc) || defined(__s390__) || \
     defined(__SH4__) || defined(__alpha__) || \
+    defined(__aarch64__) || \
     defined(_MIPS_ARCH_MIPS32R2)
 #define DOUBLE_CONVERSION_CORRECT_DOUBLE_OPERATIONS 1
 #elif defined(_M_IX86) || defined(__i386__) || defined(__i386)