diff --git a/ChangeLog b/ChangeLog
index ea39c31063..ae85ada978 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Thu Jun 25 07:08:35 2015  Koichi Sasada  <ko1@atdot.net>
+
+	* gc.c (obj_info, method_type_name): show method type name in a string
+	  instead of a number.
+
 Thu Jun 25 06:49:25 2015  Koichi Sasada  <ko1@atdot.net>
 
 	* gc.c (obj_info): show more details for T_IMEMO/imemo_ment.
diff --git a/gc.c b/gc.c
index d018190de0..2cd8c410e9 100644
--- a/gc.c
+++ b/gc.c
@@ -8838,6 +8838,28 @@ obj_type_name(VALUE obj)
 }
 
 #if RGENGC_OBJ_INFO
+
+static const char *
+method_type_name(rb_method_type_t type)
+{
+    switch (type) {
+      case VM_METHOD_TYPE_ISEQ:           return "iseq";
+      case VM_METHOD_TYPE_ATTRSET:        return "attrest";
+      case VM_METHOD_TYPE_IVAR:           return "ivar";
+      case VM_METHOD_TYPE_BMETHOD:        return "bmethod";
+      case VM_METHOD_TYPE_ALIAS:          return "alias";
+      case VM_METHOD_TYPE_REFINED:        return "refined";
+      case VM_METHOD_TYPE_CFUNC:          return "cfunc";
+      case VM_METHOD_TYPE_ZSUPER:         return "zsuper";
+      case VM_METHOD_TYPE_MISSING:        return "missing";
+      case VM_METHOD_TYPE_OPTIMIZED:      return "optimized";
+      case VM_METHOD_TYPE_UNDEF:          return "undef";
+      case VM_METHOD_TYPE_NOTIMPLEMENTED: return "notimplemented";
+    }
+    rb_bug("method_type_name: unreachable (type: %d)", type);
+}
+
+
 #define OBJ_INFO_BUFFERS_NUM  10
 #define OBJ_INFO_BUFFERS_SIZE 0x100
 static int obj_info_buffers_index = 0;
@@ -8944,8 +8966,8 @@ obj_info(VALUE obj)
 	snprintf(buff, OBJ_INFO_BUFFERS_SIZE, "%s %s", buff, imemo_name);
 	if (imemo_type(obj) == imemo_ment) {
 	    const rb_method_entry_t *me = &RANY(obj)->as.imemo.ment;
-	    snprintf(buff, OBJ_INFO_BUFFERS_SIZE, "%s (called_id: %s, type: %d, alias: %d, class: %s)", buff,
-		     rb_id2name(me->called_id), me->def->type, me->def->alias_count, obj_info(me->klass));
+	    snprintf(buff, OBJ_INFO_BUFFERS_SIZE, "%s (called_id: %s, type: %s, alias: %d, class: %s)", buff,
+		     rb_id2name(me->called_id), method_type_name(me->def->type), me->def->alias_count, obj_info(me->klass));
 	}
       }
       default: