diff --git a/ChangeLog b/ChangeLog
index 7337862857..dbf29720d1 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Sat Aug  6 09:35:30 2016  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* id_table.h (rb_id_table_iterator_result): add dummy sentinel
+	  member because C standard prohibits a trailing comma.
+
 Sat Aug  6 00:39:44 2016  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* hash.c (env_enc_str_new): make string for an environment
diff --git a/id_table.c b/id_table.c
index b8111aa86c..1d1d684745 100644
--- a/id_table.c
+++ b/id_table.c
@@ -720,6 +720,7 @@ list_id_table_delete(struct list_id_table *tbl, ID id)
 
 #define FOREACH_LAST() do {   \
     switch (ret) {            \
+      case ID_TABLE_ITERATOR_RESULT_END: \
       case ID_TABLE_CONTINUE: \
       case ID_TABLE_STOP:     \
 	break;                \
diff --git a/id_table.h b/id_table.h
index 4b4eb6fd70..b10b4ac164 100644
--- a/id_table.h
+++ b/id_table.h
@@ -9,6 +9,7 @@ enum rb_id_table_iterator_result {
     ID_TABLE_CONTINUE = ST_CONTINUE,
     ID_TABLE_STOP     = ST_STOP,
     ID_TABLE_DELETE   = ST_DELETE,
+    ID_TABLE_ITERATOR_RESULT_END
 };
 
 struct rb_id_table *rb_id_table_create(size_t size);