1 files changed, 17 insertions, 15 deletions
diff --git a/lib/rubygems/commands/mirror_command.rb b/lib/rubygems/commands/mirror_command.rb
index 75419c857a..24fb668d54 100644
--- a/lib/rubygems/commands/mirror_command.rb
+++ b/lib/rubygems/commands/mirror_command.rb
@@ -1,23 +1,25 @@
 require 'rubygems/command'
 
-class Gem::Commands::MirrorCommand < Gem::Command
-  def initialize
-    super('mirror', 'Mirror all gem files (requires rubygems-mirror)')
-    begin
-      Gem::Specification.find_by_name('rubygems-mirror').activate
-    rescue Gem::LoadError
-      # no-op
+unless defined? Gem::Commands::MirrorCommand
+  class Gem::Commands::MirrorCommand < Gem::Command
+    def initialize
+      super('mirror', 'Mirror all gem files (requires rubygems-mirror)')
+      begin
+        Gem::Specification.find_by_name('rubygems-mirror').activate
+      rescue Gem::LoadError
+        # no-op
+      end
     end
-  end
 
-  def description # :nodoc:
-    <<-EOF
+    def description # :nodoc:
+      <<-EOF
 The mirror command has been moved to the rubygems-mirror gem.
-    EOF
-  end
+      EOF
+    end
 
-  def execute
-    alert_error "Install the rubygems-mirror gem for the mirror command"
-  end
+    def execute
+      alert_error "Install the rubygems-mirror gem for the mirror command"
+    end
 
+  end
 end