diff --git a/ChangeLog b/ChangeLog
index b9b7fd1203..6733d21786 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Thu Oct 22 05:23:48 2015  KOSAKI Motohiro  <kosaki.motohiro@gmail.com>
+
+	* random.c (init_hashseed, init_siphash): extract initialize
+	  functions.
+
 Thu Oct 22 01:01:34 2015  KOSAKI Motohiro  <kosaki.motohiro@gmail.com>
 
 	* configure.in: sort AC_CHECK_HEADERS() by alphabetical order.
diff --git a/random.c b/random.c
index 76775f2d80..11b7a3febe 100644
--- a/random.c
+++ b/random.c
@@ -1465,13 +1465,10 @@ init_randomseed(struct MT *mt)
     return seed;
 }
 
-void
-Init_RandomSeed(void)
+static void
+init_hashseed(void)
 {
-    rb_random_t *r = &default_rand;
-    struct MT *mt = &r->mt;
-    VALUE seed = init_randomseed(mt);
-    int i;
+    struct MT *mt = default_mt();
 
     hashseed = genrand_int32(mt);
 #if SIZEOF_ST_INDEX_T*CHAR_BIT > 4*8
@@ -1486,12 +1483,16 @@ Init_RandomSeed(void)
     hashseed <<= 32;
     hashseed |= genrand_int32(mt);
 #endif
+}
+
+static void
+init_siphash(void)
+{
+    struct MT *mt = default_mt();
+    int i;
 
     for (i = 0; i < numberof(sipseed.u32); ++i)
 	sipseed.u32[i] = genrand_int32(mt);
-
-    rb_global_variable(&r->seed);
-    r->seed = seed;
 }
 
 st_index_t
@@ -1511,6 +1512,20 @@ rb_memhash(const void *ptr, long len)
 #endif
 }
 
+void
+Init_RandomSeed(void)
+{
+    rb_random_t *r = &default_rand;
+    struct MT *mt = &r->mt;
+    VALUE seed = init_randomseed(mt);
+
+    init_hashseed();
+    init_siphash();
+
+    rb_global_variable(&r->seed);
+    r->seed = seed;
+}
+
 static void
 Init_RandomSeed2(void)
 {