diff --git a/ext/openssl/ossl.h b/ext/openssl/ossl.h
index c3140ac3e..24d251f6a 100644
--- a/ext/openssl/ossl.h
+++ b/ext/openssl/ossl.h
@@ -17,6 +17,11 @@
 #include <errno.h>
 #include <ruby/io.h>
 #include <ruby/thread.h>
+#ifdef HAVE_RB_EXT_RACTOR_SAFE
+#include <ruby/ractor.h>
+#else
+#define RUBY_TYPED_FROZEN_SHAREABLE 0
+#endif
 #include <openssl/opensslv.h>
 
 #include <openssl/err.h>
diff --git a/ext/openssl/ossl_bn.c b/ext/openssl/ossl_bn.c
index 7393fdea5..a39bfc453 100644
--- a/ext/openssl/ossl_bn.c
+++ b/ext/openssl/ossl_bn.c
@@ -10,10 +10,6 @@
 /* modified by Michal Rokos <m.rokos@sh.cvut.cz> */
 #include "ossl.h"
 
-#ifdef HAVE_RB_EXT_RACTOR_SAFE
-#include <ruby/ractor.h>
-#endif
-
 #define NewBN(klass) \
   TypedData_Wrap_Struct((klass), &ossl_bn_type, 0)
 #define SetBN(obj, bn) do { \
@@ -41,7 +37,7 @@ static const rb_data_type_t ossl_bn_type = {
     {
 	0, ossl_bn_free,
     },
-    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED,
+    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED | RUBY_TYPED_FROZEN_SHAREABLE,
 };
 
 /*
diff --git a/ext/openssl/ossl_cipher.c b/ext/openssl/ossl_cipher.c
index cc0114f57..6552b5f3c 100644
--- a/ext/openssl/ossl_cipher.c
+++ b/ext/openssl/ossl_cipher.c
@@ -42,7 +42,7 @@ static const rb_data_type_t ossl_cipher_type = {
     {
 	0, ossl_cipher_free,
     },
-    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED,
+    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED | RUBY_TYPED_FROZEN_SHAREABLE,
 };
 
 /*
diff --git a/ext/openssl/ossl_config.c b/ext/openssl/ossl_config.c
index 55875028b..d6341fa52 100644
--- a/ext/openssl/ossl_config.c
+++ b/ext/openssl/ossl_config.c
@@ -22,7 +22,7 @@ static const rb_data_type_t ossl_config_type = {
     {
         0, nconf_free,
     },
-    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED,
+    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED | RUBY_TYPED_FROZEN_SHAREABLE,
 };
 
 CONF *
diff --git a/ext/openssl/ossl_digest.c b/ext/openssl/ossl_digest.c
index 00ec8931a..4ad93919c 100644
--- a/ext/openssl/ossl_digest.c
+++ b/ext/openssl/ossl_digest.c
@@ -35,7 +35,7 @@ static const rb_data_type_t ossl_digest_type = {
     {
 	0, ossl_digest_free,
     },
-    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED,
+    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED | RUBY_TYPED_FROZEN_SHAREABLE,
 };
 
 /*
diff --git a/ext/openssl/ossl_engine.c b/ext/openssl/ossl_engine.c
index 294d58ade..b68531750 100644
--- a/ext/openssl/ossl_engine.c
+++ b/ext/openssl/ossl_engine.c
@@ -78,7 +78,7 @@ static const rb_data_type_t ossl_engine_type = {
     {
 	0, ossl_engine_free,
     },
-    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED,
+    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED | RUBY_TYPED_FROZEN_SHAREABLE,
 };
 
 /*
diff --git a/ext/openssl/ossl_hmac.c b/ext/openssl/ossl_hmac.c
index b1163f612..99f36c1d0 100644
--- a/ext/openssl/ossl_hmac.c
+++ b/ext/openssl/ossl_hmac.c
@@ -42,7 +42,7 @@ static const rb_data_type_t ossl_hmac_type = {
     {
 	0, ossl_hmac_free,
     },
-    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED,
+    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED | RUBY_TYPED_FROZEN_SHAREABLE,
 };
 
 static VALUE
diff --git a/ext/openssl/ossl_ns_spki.c b/ext/openssl/ossl_ns_spki.c
index e822d5e0a..5c9147ff6 100644
--- a/ext/openssl/ossl_ns_spki.c
+++ b/ext/openssl/ossl_ns_spki.c
@@ -50,7 +50,7 @@ static const rb_data_type_t ossl_netscape_spki_type = {
     {
 	0, ossl_netscape_spki_free,
     },
-    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED,
+    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED | RUBY_TYPED_FROZEN_SHAREABLE,
 };
 
 static VALUE
diff --git a/ext/openssl/ossl_ocsp.c b/ext/openssl/ossl_ocsp.c
index 9796d44a2..02bb9cfe6 100644
--- a/ext/openssl/ossl_ocsp.c
+++ b/ext/openssl/ossl_ocsp.c
@@ -86,7 +86,7 @@ static const rb_data_type_t ossl_ocsp_request_type = {
     {
 	0, ossl_ocsp_request_free,
     },
-    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED,
+    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED | RUBY_TYPED_FROZEN_SHAREABLE,
 };
 
 static void
@@ -100,7 +100,7 @@ static const rb_data_type_t ossl_ocsp_response_type = {
     {
 	0, ossl_ocsp_response_free,
     },
-    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED,
+    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED | RUBY_TYPED_FROZEN_SHAREABLE,
 };
 
 static void
@@ -114,7 +114,7 @@ static const rb_data_type_t ossl_ocsp_basicresp_type = {
     {
 	0, ossl_ocsp_basicresp_free,
     },
-    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED,
+    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED | RUBY_TYPED_FROZEN_SHAREABLE,
 };
 
 static void
@@ -128,7 +128,7 @@ static const rb_data_type_t ossl_ocsp_singleresp_type = {
     {
 	0, ossl_ocsp_singleresp_free,
     },
-    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED,
+    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED | RUBY_TYPED_FROZEN_SHAREABLE,
 };
 
 static void
@@ -142,7 +142,7 @@ static const rb_data_type_t ossl_ocsp_certid_type = {
     {
 	0, ossl_ocsp_certid_free,
     },
-    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED,
+    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED | RUBY_TYPED_FROZEN_SHAREABLE,
 };
 
 /*
diff --git a/ext/openssl/ossl_pkcs12.c b/ext/openssl/ossl_pkcs12.c
index 1fcb1a88d..c4401eed7 100644
--- a/ext/openssl/ossl_pkcs12.c
+++ b/ext/openssl/ossl_pkcs12.c
@@ -44,7 +44,7 @@ static const rb_data_type_t ossl_pkcs12_type = {
     {
 	0, ossl_pkcs12_free,
     },
-    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED,
+    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED | RUBY_TYPED_FROZEN_SHAREABLE,
 };
 
 static VALUE
diff --git a/ext/openssl/ossl_pkcs7.c b/ext/openssl/ossl_pkcs7.c
index b7e6d330b..25ec2787f 100644
--- a/ext/openssl/ossl_pkcs7.c
+++ b/ext/openssl/ossl_pkcs7.c
@@ -65,7 +65,7 @@ const rb_data_type_t ossl_pkcs7_type = {
     {
 	0, ossl_pkcs7_free,
     },
-    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED,
+    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED | RUBY_TYPED_FROZEN_SHAREABLE,
 };
 
 static void
@@ -79,7 +79,7 @@ static const rb_data_type_t ossl_pkcs7_signer_info_type = {
     {
 	0, ossl_pkcs7_signer_info_free,
     },
-    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED,
+    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED | RUBY_TYPED_FROZEN_SHAREABLE,
 };
 
 static void
@@ -93,7 +93,7 @@ static const rb_data_type_t ossl_pkcs7_recip_info_type = {
     {
 	0, ossl_pkcs7_recip_info_free,
     },
-    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED,
+    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED | RUBY_TYPED_FROZEN_SHAREABLE,
 };
 
 /*
diff --git a/ext/openssl/ossl_pkey.c b/ext/openssl/ossl_pkey.c
index 6af2245f3..b95b1f02d 100644
--- a/ext/openssl/ossl_pkey.c
+++ b/ext/openssl/ossl_pkey.c
@@ -35,7 +35,7 @@ const rb_data_type_t ossl_evp_pkey_type = {
     {
 	0, ossl_evp_pkey_free,
     },
-    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED,
+    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED | RUBY_TYPED_FROZEN_SHAREABLE,
 };
 
 static VALUE
diff --git a/ext/openssl/ossl_pkey_ec.c b/ext/openssl/ossl_pkey_ec.c
index 4b3a1fd0f..8ee5ca868 100644
--- a/ext/openssl/ossl_pkey_ec.c
+++ b/ext/openssl/ossl_pkey_ec.c
@@ -586,7 +586,7 @@ static const rb_data_type_t ossl_ec_group_type = {
     {
 	0, ossl_ec_group_free,
     },
-    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED,
+    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED | RUBY_TYPED_FROZEN_SHAREABLE,
 };
 
 static VALUE
@@ -1171,7 +1171,7 @@ static const rb_data_type_t ossl_ec_point_type = {
     {
 	0, ossl_ec_point_free,
     },
-    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED,
+    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED | RUBY_TYPED_FROZEN_SHAREABLE,
 };
 
 static VALUE
diff --git a/ext/openssl/ossl_provider.c b/ext/openssl/ossl_provider.c
index d1f6c5d42..ac0da4669 100644
--- a/ext/openssl/ossl_provider.c
+++ b/ext/openssl/ossl_provider.c
@@ -27,7 +27,7 @@ static const rb_data_type_t ossl_provider_type = {
     {
         0,
     },
-    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED,
+    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED | RUBY_TYPED_FROZEN_SHAREABLE,
 };
 
 /*
diff --git a/ext/openssl/ossl_ssl.c b/ext/openssl/ossl_ssl.c
index 457630ddc..19f4006c1 100644
--- a/ext/openssl/ossl_ssl.c
+++ b/ext/openssl/ossl_ssl.c
@@ -77,7 +77,7 @@ static const rb_data_type_t ossl_sslctx_type = {
     {
         ossl_sslctx_mark, ossl_sslctx_free,
     },
-    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED,
+    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED | RUBY_TYPED_FROZEN_SHAREABLE,
 };
 
 static VALUE
@@ -1571,7 +1571,7 @@ const rb_data_type_t ossl_ssl_type = {
     {
         ossl_ssl_mark, ossl_ssl_free,
     },
-    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED,
+    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED | RUBY_TYPED_FROZEN_SHAREABLE,
 };
 
 static VALUE
diff --git a/ext/openssl/ossl_ssl_session.c b/ext/openssl/ossl_ssl_session.c
index c5df902c6..7b5240b1e 100644
--- a/ext/openssl/ossl_ssl_session.c
+++ b/ext/openssl/ossl_ssl_session.c
@@ -19,7 +19,7 @@ const rb_data_type_t ossl_ssl_session_type = {
     {
 	0, ossl_ssl_session_free,
     },
-    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED,
+    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED | RUBY_TYPED_FROZEN_SHAREABLE,
 };
 
 static VALUE ossl_ssl_session_alloc(VALUE klass)
diff --git a/ext/openssl/ossl_ts.c b/ext/openssl/ossl_ts.c
index d6a5fc989..3bd7de9b8 100644
--- a/ext/openssl/ossl_ts.c
+++ b/ext/openssl/ossl_ts.c
@@ -83,7 +83,7 @@ static const rb_data_type_t ossl_ts_req_type = {
     {
         0, ossl_ts_req_free,
     },
-    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED,
+    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED | RUBY_TYPED_FROZEN_SHAREABLE,
 };
 
 static void
@@ -97,7 +97,7 @@ static  const rb_data_type_t ossl_ts_resp_type = {
     {
         0, ossl_ts_resp_free,
     },
-    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED,
+    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED | RUBY_TYPED_FROZEN_SHAREABLE,
 };
 
 static void
@@ -111,7 +111,7 @@ static const rb_data_type_t ossl_ts_token_info_type = {
     {
         0, ossl_ts_token_info_free,
     },
-    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED,
+    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED | RUBY_TYPED_FROZEN_SHAREABLE,
 };
 
 static VALUE
diff --git a/ext/openssl/ossl_x509attr.c b/ext/openssl/ossl_x509attr.c
index 967fe89f0..090f942e7 100644
--- a/ext/openssl/ossl_x509attr.c
+++ b/ext/openssl/ossl_x509attr.c
@@ -41,7 +41,7 @@ static const rb_data_type_t ossl_x509attr_type = {
     {
 	0, ossl_x509attr_free,
     },
-    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED,
+    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED | RUBY_TYPED_FROZEN_SHAREABLE,
 };
 
 /*
diff --git a/ext/openssl/ossl_x509cert.c b/ext/openssl/ossl_x509cert.c
index 846dd0701..ad61152e1 100644
--- a/ext/openssl/ossl_x509cert.c
+++ b/ext/openssl/ossl_x509cert.c
@@ -41,7 +41,7 @@ static const rb_data_type_t ossl_x509_type = {
     {
 	0, ossl_x509_free,
     },
-    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED,
+    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED | RUBY_TYPED_FROZEN_SHAREABLE,
 };
 
 /*
diff --git a/ext/openssl/ossl_x509crl.c b/ext/openssl/ossl_x509crl.c
index 368270ce1..828033bad 100644
--- a/ext/openssl/ossl_x509crl.c
+++ b/ext/openssl/ossl_x509crl.c
@@ -41,7 +41,7 @@ static const rb_data_type_t ossl_x509crl_type = {
     {
 	0, ossl_x509crl_free,
     },
-    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED,
+    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED | RUBY_TYPED_FROZEN_SHAREABLE,
 };
 
 /*
diff --git a/ext/openssl/ossl_x509ext.c b/ext/openssl/ossl_x509ext.c
index 7f47cd7cc..fc04a2468 100644
--- a/ext/openssl/ossl_x509ext.c
+++ b/ext/openssl/ossl_x509ext.c
@@ -55,7 +55,7 @@ static const rb_data_type_t ossl_x509ext_type = {
     {
 	0, ossl_x509ext_free,
     },
-    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED,
+    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED | RUBY_TYPED_FROZEN_SHAREABLE,
 };
 
 /*
@@ -108,7 +108,7 @@ static const rb_data_type_t ossl_x509extfactory_type = {
     {
 	0, ossl_x509extfactory_free,
     },
-    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED,
+    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED | RUBY_TYPED_FROZEN_SHAREABLE,
 };
 
 static VALUE
diff --git a/ext/openssl/ossl_x509name.c b/ext/openssl/ossl_x509name.c
index 5060be92c..87e3f6a5b 100644
--- a/ext/openssl/ossl_x509name.c
+++ b/ext/openssl/ossl_x509name.c
@@ -46,7 +46,7 @@ static const rb_data_type_t ossl_x509name_type = {
     {
 	0, ossl_x509name_free,
     },
-    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED,
+    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED | RUBY_TYPED_FROZEN_SHAREABLE,
 };
 
 /*
diff --git a/ext/openssl/ossl_x509req.c b/ext/openssl/ossl_x509req.c
index 37ba03728..fbe6bc7d3 100644
--- a/ext/openssl/ossl_x509req.c
+++ b/ext/openssl/ossl_x509req.c
@@ -41,7 +41,7 @@ static const rb_data_type_t ossl_x509req_type = {
     {
 	0, ossl_x509req_free,
     },
-    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED,
+    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED | RUBY_TYPED_FROZEN_SHAREABLE,
 };
 
 /*
diff --git a/ext/openssl/ossl_x509revoked.c b/ext/openssl/ossl_x509revoked.c
index 5b82470c8..ebc597810 100644
--- a/ext/openssl/ossl_x509revoked.c
+++ b/ext/openssl/ossl_x509revoked.c
@@ -41,7 +41,7 @@ static const rb_data_type_t ossl_x509rev_type = {
     {
 	0, ossl_x509rev_free,
     },
-    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED,
+    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED | RUBY_TYPED_FROZEN_SHAREABLE,
 };
 
 /*
diff --git a/ext/openssl/ossl_x509store.c b/ext/openssl/ossl_x509store.c
index 670519feb..3f6d3423a 100644
--- a/ext/openssl/ossl_x509store.c
+++ b/ext/openssl/ossl_x509store.c
@@ -133,7 +133,7 @@ static const rb_data_type_t ossl_x509store_type = {
     {
         ossl_x509store_mark, ossl_x509store_free,
     },
-    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED,
+    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED | RUBY_TYPED_FROZEN_SHAREABLE,
 };
 
 /*
@@ -541,7 +541,7 @@ static const rb_data_type_t ossl_x509stctx_type = {
     {
         ossl_x509stctx_mark, ossl_x509stctx_free,
     },
-    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED,
+    0, 0, RUBY_TYPED_FREE_IMMEDIATELY | RUBY_TYPED_WB_PROTECTED | RUBY_TYPED_FROZEN_SHAREABLE,
 };
 
 static VALUE
diff --git a/lib/openssl/ssl.rb b/lib/openssl/ssl.rb
index 2186f5f43..245ddffe7 100644
--- a/lib/openssl/ssl.rb
+++ b/lib/openssl/ssl.rb
@@ -93,6 +93,7 @@ class SSLContext
       DEFAULT_CERT_STORE = OpenSSL::X509::Store.new # :nodoc:
       DEFAULT_CERT_STORE.set_default_paths
       DEFAULT_CERT_STORE.flags = OpenSSL::X509::V_FLAG_CRL_CHECK_ALL
+      DEFAULT_CERT_STORE.freeze
 
       # A callback invoked when DH parameters are required for ephemeral DH key
       # exchange.