2 files changed, 5 insertions, 1 deletions
diff --git a/ext/openssl/lib/openssl/ssl.rb b/ext/openssl/lib/openssl/ssl.rb
index ef2b3f1c64..1c0cc2fd00 100644
--- a/ext/openssl/lib/openssl/ssl.rb
+++ b/ext/openssl/lib/openssl/ssl.rb
@@ -128,6 +128,10 @@ module OpenSSL
         end
         return params
       end
+
+      def tmp_dh_callback=(value)
+        @tmp_dh_callback = value || DEFAULT_TMP_DH_CALLBACK
+      end
     end
 
     module SocketForwarder
diff --git a/ext/openssl/ossl_ssl.c b/ext/openssl/ossl_ssl.c
index 3e756eae5f..ca5f43cf0e 100644
--- a/ext/openssl/ossl_ssl.c
+++ b/ext/openssl/ossl_ssl.c
@@ -2122,7 +2122,7 @@ Init_ossl_ssl(void)
      * The callback must return an OpenSSL::PKey::DH instance of the correct
      * key length.
      */
-    rb_attr(cSSLContext, rb_intern("tmp_dh_callback"), 1, 1, Qfalse);
+    rb_attr(cSSLContext, rb_intern("tmp_dh_callback"), 1, 0, Qfalse);
 
     /*
      * Sets the context in which a session can be reused.  This allows