--- a/js/src/configure.in.old	2009-11-08 19:50:54.299642792 -0500
+++ b/js/src/configure.in	2009-11-08 19:57:49.235621814 -0500
@@ -2465,6 +2465,10 @@
     ENABLE_JIT=1
     NANOJIT_ARCH=i386
     ;;
+x86_64*-*)
+    ENABLE_JIT=1
+    NANOJIT_ARCH=X64
+    ;;
 arm*-*)
     ENABLE_JIT=1
     NANOJIT_ARCH=ARM