diff --git a/ChangeLog b/ChangeLog
index bc62802a09..de305f7dd0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Mon Jun 13 13:04:20 2011  Martin Bosslet  <Martin.Bosslet@googlemail.com>
+
+	* ext/openssl/ossl_digest.c: fix error for digests that have no oid
+	(e.g. DSS1).
+	* test/openssl/test_digest.c: add tests for this.
+
 Mon Jun 13 12:51:51 2011  NARUSE, Yui  <naruse@ruby-lang.org>
 
 	* lib/yaml.rb: load psych only when syck is not loaded.
diff --git a/ext/openssl/ossl_digest.c b/ext/openssl/ossl_digest.c
index ebfca120da..cb0cade1bf 100644
--- a/ext/openssl/ossl_digest.c
+++ b/ext/openssl/ossl_digest.c
@@ -41,9 +41,12 @@ GetDigestPtr(VALUE obj)
     if (TYPE(obj) == T_STRING) {
     	const char *name = StringValueCStr(obj);
 
-	oid = OBJ_txt2obj(name, 0);
-	md = EVP_get_digestbyobj(oid);
-	ASN1_OBJECT_free(oid);
+	md = EVP_get_digestbyname(name);
+	if (!md) {
+	    oid = OBJ_txt2obj(name, 0);
+	    md = EVP_get_digestbyobj(oid);
+	    ASN1_OBJECT_free(oid);
+	}
 	if(!md)
             ossl_raise(rb_eRuntimeError, "Unsupported digest algorithm (%s).", name);
     } else {
diff --git a/test/openssl/test_digest.rb b/test/openssl/test_digest.rb
index ce0d85fe55..5f9a563d1c 100644
--- a/test/openssl/test_digest.rb
+++ b/test/openssl/test_digest.rb
@@ -56,6 +56,18 @@ class OpenSSL::TestDigest < Test::Unit::TestCase
     assert_equal(dig1, dig2, "reset")
   end
 
+  def test_digest_constants
+    algs = %w(DSS1 MD4 MD5 MDC2 RIPEMD160 SHA SHA1)
+    if OpenSSL::OPENSSL_VERSION_NUMBER > 0x00908000
+      algs += %w(SHA224 SHA256 SHA384 SHA512)
+    end
+    algs.each do |alg|
+      assert_not_nil(OpenSSL::Digest.new(alg))
+      klass = OpenSSL::Digest.const_get(alg)
+      assert_not_nil(klass.new)
+    end
+  end
+
   def test_digest_by_oid_and_name
     check_digest(OpenSSL::ASN1::ObjectId.new("MD5"))
     check_digest(OpenSSL::ASN1::ObjectId.new("SHA1"))