diff --git a/ChangeLog b/ChangeLog
index 8efc5a307d..112699e24b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+Thu Jun  5 23:40:08 2008  Yusuke Endoh  <mame@tsg.ne.jp>
+
+	* gc.c (rb_objspace_alloc): this function is needed only when
+	  ENABLE_VM_OBJSPACE macro is defined.
+
+	* vm.c: ditto.
+
 Thu Jun  5 23:31:21 2008  Yusuke Endoh  <mame@tsg.ne.jp>
 
 	* test/stringio/test_stringio.rb: add tests to achieve over 95% test
diff --git a/gc.c b/gc.c
index 245b8ee2d9..0bd140ae4e 100644
--- a/gc.c
+++ b/gc.c
@@ -201,6 +201,7 @@ static rb_objspace_t rb_objspace = {{GC_MALLOC_LIMIT}, {HEAP_MIN_SLOTS}};
 #define mark_stack_overflow	objspace->markstack.overflow
 #define global_List		objspace->global_list
 
+#if defined(ENABLE_VM_OBJSPACE) && ENABLE_VM_OBJSPACE
 rb_objspace_t *
 rb_objspace_alloc(void)
 {
@@ -210,6 +211,7 @@ rb_objspace_alloc(void)
 
     return objspace;
 }
+#endif
 
 /* tiny heap size */
 /* 32KB */
diff --git a/vm.c b/vm.c
index 7c859110f1..0194ea6750 100644
--- a/vm.c
+++ b/vm.c
@@ -1728,7 +1728,9 @@ Init_VM(void)
     vm_init_redefined_flag();
 }
 
+#if defined(ENABLE_VM_OBJSPACE) && ENABLE_VM_OBJSPACE
 struct rb_objspace *rb_objspace_alloc(void);
+#endif
 
 void
 Init_BareVM(void)