diff --git a/ChangeLog b/ChangeLog
index d12b4917b5..83246e4816 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Sun Aug 17 19:41:40 2014  Kazuki Tsujimoto  <kazuki@callcc.net>
+
+	* gc.c (obj_memsize_of): don't calculate memsize of T_NODE
+	  when called from check_gen_consistency. It fixes segmentation
+	  fault on RGENGC_CHECK_MODE >= 1 introduced by r47188.
+
 Sun Aug 17 17:08:12 2014  Masaki Suketa <masaki.suketa@nifty.ne.jp>
 
 	* ext/win32ole/win32ole.c (ole_invoke): use RHASH_SIZE instead of
diff --git a/gc.c b/gc.c
index 0d094663b1..cd65fc10d4 100644
--- a/gc.c
+++ b/gc.c
@@ -690,7 +690,7 @@ static void gc_mark(rb_objspace_t *objspace, VALUE ptr);
 static void gc_mark_maybe(rb_objspace_t *objspace, VALUE ptr);
 static void gc_mark_children(rb_objspace_t *objspace, VALUE ptr);
 
-static size_t obj_memsize_of(VALUE obj, int use_tdata);
+static size_t obj_memsize_of(VALUE obj, int use_all_types);
 static VALUE gc_verify_internal_consistency(VALUE self);
 
 static double getrusage_time(void);
@@ -2497,7 +2497,7 @@ size_t rb_generic_ivar_memsize(VALUE);
 #include "regint.h"
 
 static size_t
-obj_memsize_of(VALUE obj, int use_tdata)
+obj_memsize_of(VALUE obj, int use_all_types)
 {
     size_t size = 0;
 
@@ -2557,7 +2557,7 @@ obj_memsize_of(VALUE obj, int use_tdata)
 	}
 	break;
       case T_DATA:
-	if (use_tdata) size += rb_objspace_data_type_memsize(obj);
+	if (use_all_types) size += rb_objspace_data_type_memsize(obj);
 	break;
       case T_MATCH:
 	if (RMATCH(obj)->rmatch) {
@@ -2590,7 +2590,7 @@ obj_memsize_of(VALUE obj, int use_tdata)
 	break;
 
       case T_NODE:
-	size += rb_node_memsize(obj);
+	if (use_all_types) size += rb_node_memsize(obj);
 	break;
 
       case T_STRUCT: