diff --git a/lib/sshkit.rb b/lib/sshkit.rb
index cae4feba..b640ca3a 100644
--- a/lib/sshkit.rb
+++ b/lib/sshkit.rb
@@ -4,7 +4,7 @@ module SSHKit
 
   class << self
 
-    attr_accessor :config
+    attr_writer :config
 
     def configure
       @@config ||= Configuration.new
diff --git a/lib/sshkit/backends/connection_pool.rb b/lib/sshkit/backends/connection_pool.rb
index e1b0f0f6..3b093103 100644
--- a/lib/sshkit/backends/connection_pool.rb
+++ b/lib/sshkit/backends/connection_pool.rb
@@ -78,10 +78,12 @@ def close_connections
     end
   end
 
-  private
+  protected
 
   attr_reader :caches, :timed_out_connections
 
+  private
+
   def cache_enabled?
     idle_timeout && idle_timeout > 0
   end
diff --git a/lib/sshkit/backends/connection_pool/cache.rb b/lib/sshkit/backends/connection_pool/cache.rb
index f29f2ba1..dbce2d39 100644
--- a/lib/sshkit/backends/connection_pool/cache.rb
+++ b/lib/sshkit/backends/connection_pool/cache.rb
@@ -53,10 +53,12 @@ def clear
     end
   end
 
-  private
+  protected
 
   attr_reader :connections, :idle_timeout, :closer
 
+  private
+
   def fresh?(expires_at)
     expires_at > Time.now
   end
diff --git a/lib/sshkit/backends/netssh.rb b/lib/sshkit/backends/netssh.rb
index c916860e..f3293046 100644
--- a/lib/sshkit/backends/netssh.rb
+++ b/lib/sshkit/backends/netssh.rb
@@ -5,6 +5,8 @@ module Net
   module SSH
     class Config
       class << self
+        remove_method :default_files
+
         def default_files
           @@default_files + [File.join(Dir.pwd, '.ssh/config')]
         end
diff --git a/lib/sshkit/configuration.rb b/lib/sshkit/configuration.rb
index a9e8a396..333ac05f 100644
--- a/lib/sshkit/configuration.rb
+++ b/lib/sshkit/configuration.rb
@@ -2,7 +2,7 @@ module SSHKit
 
   class Configuration
 
-    attr_accessor :umask, :output_verbosity
+    attr_accessor :umask
     attr_writer :output, :backend, :default_env, :default_runner
 
     def output
diff --git a/lib/sshkit/host.rb b/lib/sshkit/host.rb
index cd532469..f4a1db8d 100644
--- a/lib/sshkit/host.rb
+++ b/lib/sshkit/host.rb
@@ -99,7 +99,7 @@ def properties
   class SimpleHostParser
 
     def self.suitable?(host_string)
-      !host_string.match(/[:|@]/)
+      !host_string.match(/:|@/)
     end
 
     def initialize(host_string)
@@ -127,7 +127,7 @@ def attributes
   class HostWithPortParser < SimpleHostParser
 
     def self.suitable?(host_string)
-      !host_string.match(/[@|\[|\]]/)
+      !host_string.match(/@|\[|\]/)
     end
 
     def port