diff --git a/lib/rubygems/commands/uninstall_command.rb b/lib/rubygems/commands/uninstall_command.rb
index 68e048c010..c1a9dbba32 100644
--- a/lib/rubygems/commands/uninstall_command.rb
+++ b/lib/rubygems/commands/uninstall_command.rb
@@ -143,7 +143,7 @@ that is a dependency of an existing gem.  You can use the
       uninstall_gem spec.name
     end
 
-    alert "Uninstalled all gems in #{options[:install_dir]}"
+    alert "Uninstalled all gems in #{options[:install_dir] || Gem.dir}"
   end
 
   def uninstall_specific
diff --git a/test/rubygems/test_gem_commands_uninstall_command.rb b/test/rubygems/test_gem_commands_uninstall_command.rb
index 1f71b4ce1d..ee63847c84 100644
--- a/test/rubygems/test_gem_commands_uninstall_command.rb
+++ b/test/rubygems/test_gem_commands_uninstall_command.rb
@@ -361,6 +361,7 @@ class TestGemCommandsUninstallCommand < Gem::InstallerTestCase
     end
 
     assert_equal %w[default-1], Gem::Specification.all_names.sort
+    assert_equal "INFO:  Uninstalled all gems in #{@gemhome}", @ui.output.split("\n").last
   end
 
   def test_execute_outside_gem_home