diff --git a/ChangeLog b/ChangeLog
index 93f46263c2..2e0f73770f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Thu Oct  4 23:40:04 2012  Narihiro Nakamura  <authornari@gmail.com>
+
+	* gc.c (init_heap): call init_mark_stack before to allocate
+	  altstack. This change avoid the stack overflow at the signal
+	  handler on 32bit, but I don't understand reason... [Feature #7095]
+
 Thu Oct  4 22:39:27 2012  Koichi Sasada  <ko1@atdot.net>
 
 	* insns.def (getlocal, setlocal): remove old getlocal/setlocal
diff --git a/gc.c b/gc.c
index 5d0c1befd6..4daacd5a09 100644
--- a/gc.c
+++ b/gc.c
@@ -587,6 +587,8 @@ static void
 init_heap(rb_objspace_t *objspace)
 {
     add_heap_slots(objspace, HEAP_MIN_SLOTS / HEAP_OBJ_LIMIT);
+    init_mark_stack(&objspace->mark_stack);
+
 #ifdef USE_SIGALTSTACK
     {
 	/* altstack of another threads are allocated in another place */
@@ -599,7 +601,6 @@ init_heap(rb_objspace_t *objspace)
 
     objspace->profile.invoke_time = getrusage_time();
     finalizer_table = st_init_numtable();
-    init_mark_stack(&objspace->mark_stack);
 }
 
 static void