diff --git a/ChangeLog b/ChangeLog
index e35ed05330..f1e82de1e8 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Tue Aug  5 16:13:05 2008  Shugo Maeda  <shugo@ruby-lang.org>
+
+	* lib/net/imap.rb (disconnect): do not refer SSL::SSLSocket for
+	  environments without OpenSSL. fixed [ruby-dev:35755].
+
 Tue Aug  5 14:19:22 2008  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* file.c (rb_stat_mode): generalized st_mode mask.
diff --git a/lib/net/imap.rb b/lib/net/imap.rb
index 4c63ddd325..64011e69cc 100644
--- a/lib/net/imap.rb
+++ b/lib/net/imap.rb
@@ -287,9 +287,11 @@ module Net
 
     # Disconnects from the server.
     def disconnect
-      if SSL::SSLSocket === @sock
+      begin
+        # try to call SSL::SSLSocket#io.
         @sock.io.shutdown
-      else
+      rescue NoMethodError
+        # @sock is not an SSL::SSLSocket.
         @sock.shutdown
       end
       @receiver_thread.join