diff --git a/ext/openssl/ossl_asn1.c b/ext/openssl/ossl_asn1.c
index 7b6c973803..3c048ab926 100644
--- a/ext/openssl/ossl_asn1.c
+++ b/ext/openssl/ossl_asn1.c
@@ -1824,6 +1824,7 @@ do{\
     rb_define_method(cASN1EndOfContent, "to_der", ossl_asn1eoc_to_der, 0);
 
     class_tag_map = rb_hash_new();
+    rb_gc_register_mark_object(class_tag_map);
     rb_hash_aset(class_tag_map, cASN1EndOfContent, INT2NUM(V_ASN1_EOC));
     rb_hash_aset(class_tag_map, cASN1Boolean, INT2NUM(V_ASN1_BOOLEAN));
     rb_hash_aset(class_tag_map, cASN1Integer, INT2NUM(V_ASN1_INTEGER));
diff --git a/test/openssl/test_asn1.rb b/test/openssl/test_asn1.rb
index 1170703775..cc11301804 100644
--- a/test/openssl/test_asn1.rb
+++ b/test/openssl/test_asn1.rb
@@ -635,6 +635,11 @@ class  OpenSSL::TestASN1 < OpenSSL::TestCase
     assert_equal data, seq.entries
   end
 
+  def test_gc_stress
+    skip "very time consuming test"
+    assert_ruby_status(['--disable-gems', '-eGC.stress=true', '-erequire "openssl.so"'])
+  end
+
   private
 
   def B(ary)
diff --git a/version.h b/version.h
index 97b187b82b..9fca24e31d 100644
--- a/version.h
+++ b/version.h
@@ -1,6 +1,6 @@
 #define RUBY_VERSION "2.5.8"
 #define RUBY_RELEASE_DATE "2020-03-31"
-#define RUBY_PATCHLEVEL 212
+#define RUBY_PATCHLEVEL 213
 
 #define RUBY_RELEASE_YEAR 2020
 #define RUBY_RELEASE_MONTH 3