diff --git a/ChangeLog b/ChangeLog
index acba651c9a..ab621f920e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Sun Oct  2 07:51:20 2016  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* string.c (rb_str_hash_m): hash values may be negative.
+
 Sun Oct  2 02:04:12 2016  NAKAMURA Usaku  <usa@ruby-lang.org>
 
 	* string.c (rb_str_hash_m): st_index_t is not guaranteed as the same
diff --git a/string.c b/string.c
index 1c27c89e8b..57b4e9ac15 100644
--- a/string.c
+++ b/string.c
@@ -2964,9 +2964,9 @@ rb_str_hash_m(VALUE str)
 {
     st_index_t hval = rb_str_hash(str);
 #if SIZEOF_LONG == SIZEOF_VOIDP
-    return ULONG2NUM(hval);
+    return LONG2FIX((long)hval);
 #elif SIZEOF_LONG_LONG == SIZEOF_VOIDP
-    return ULL2NUM(hval);
+    return LL2NUM((LONG_LONG)hval);
 #else
 # error unsupported platform
 #endif