--- a/src/runtime/thread.c
+++ b/src/runtime/thread.c
@@ -163,7 +163,7 @@
     SetSymbolValue(BINDING_STACK_START,(lispobj)th->binding_stack_start,th);
     SetSymbolValue(CONTROL_STACK_START,(lispobj)th->control_stack_start,th);
     SetSymbolValue(CONTROL_STACK_END,(lispobj)th->control_stack_end,th);
-#ifdef LISP_FEATURE_X86
+#if defined(LISP_FEATURE_X86) || defined (LISP_FEATURE_X86_64)
     SetSymbolValue(BINDING_STACK_POINTER,(lispobj)th->binding_stack_pointer,th);
     SetSymbolValue(ALIEN_STACK,(lispobj)th->alien_stack_pointer,th);
     SetSymbolValue(PSEUDO_ATOMIC_ATOMIC,(lispobj)th->pseudo_atomic_atomic,th);