Index: gc.h
===================================================================
--- gc.h	(revision 40635)
+++ gc.h	(revision 40636)
@@ -2,7 +2,7 @@
 #ifndef RUBY_GC_H
 #define RUBY_GC_H 1
 
-#if defined(__x86_64__) && defined(__GNUC__) && !defined(__native_client__)
+#if defined(__x86_64__) && !defined(_ILP32) && defined(__GNUC__) && !defined(__native_client__)
 #define SET_MACHINE_STACK_END(p) __asm__ __volatile__ ("movq\t%%rsp, %0" : "=r" (*(p)))
 #elif defined(__i386) && defined(__GNUC__) && !defined(__native_client__)
 #define SET_MACHINE_STACK_END(p) __asm__ __volatile__ ("movl\t%%esp, %0" : "=r" (*(p)))