diff --git a/ChangeLog b/ChangeLog
index 8526a7152c..e71aa2cb33 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Thu Apr 28 17:03:17 2016  Nicholas Maccharoli  <nmaccharoli@gmail.com>
+
+	* hash.c (rb_hash_update_{block,func}_callback): dry up hash
+	  update callback code.  [Fix GH-1338]
+
 Thu Apr 28 16:52:05 2016  NARUSE, Yui  <naruse@ruby-lang.org>
 
 	* re.c (rb_reg_prepare_enc): use rb_enc_asciicompat(enc) instead of
diff --git a/hash.c b/hash.c
index dfc54f0bb9..19f565ad74 100644
--- a/hash.c
+++ b/hash.c
@@ -2291,12 +2291,11 @@ rb_hash_update_block_callback(st_data_t *key, st_data_t *value, struct update_ar
     if (existing) {
 	newvalue = rb_yield_values(3, (VALUE)*key, (VALUE)*value, newvalue);
 	arg->old_value = *value;
-	arg->new_value = newvalue;
     }
     else {
 	arg->new_key = *key;
-	arg->new_value = newvalue;
     }
+    arg->new_value = newvalue;
     *value = newvalue;
     return ST_CONTINUE;
 }
@@ -2362,12 +2361,11 @@ rb_hash_update_func_callback(st_data_t *key, st_data_t *value, struct update_arg
     if (existing) {
 	newvalue = (*uf_arg->func)((VALUE)*key, (VALUE)*value, newvalue);
 	arg->old_value = *value;
-	arg->new_value = newvalue;
     }
     else {
 	arg->new_key = *key;
-	arg->new_value = newvalue;
     }
+    arg->new_value = newvalue;
     *value = newvalue;
     return ST_CONTINUE;
 }