diff --git a/ChangeLog b/ChangeLog
index 221bd7e068..70ae1d532d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Fri Mar 26 22:58:10 2010  Yusuke Endoh  <mame@tsg.ne.jp>
+
+	* ext/openssl/ossl_x509store.c (ossl_x509store_initialize): initialize
+	  store->ex_data.sk.  [ruby-core:28907] [ruby-core:23971]
+	  [ruby-core:18121]
+
 Fri Mar 26 19:55:41 2010  Akinori MUSHA  <knu@iDaemons.org>
 
 	* Makefile.in (DOXYGEN): Define a missing variable DOXYGEN.  Build
diff --git a/ext/openssl/ossl_x509store.c b/ext/openssl/ossl_x509store.c
index 23fb952305..e9923c0475 100644
--- a/ext/openssl/ossl_x509store.c
+++ b/ext/openssl/ossl_x509store.c
@@ -130,6 +130,7 @@ ossl_x509store_initialize(int argc, VALUE *argv, VALUE self)
 
 /* BUG: This method takes any number of arguments but appears to ignore them. */
     GetX509Store(self, store);
+    store->ex_data.sk = NULL;
     X509_STORE_set_verify_cb_func(store, ossl_verify_cb);
     ossl_x509store_set_vfy_cb(self, Qnil);