diff --git a/app/controllers/admin_controller.rb b/app/controllers/admin_controller.rb
index 75b2c31c..969de977 100644
--- a/app/controllers/admin_controller.rb
+++ b/app/controllers/admin_controller.rb
@@ -48,19 +48,25 @@ class AdminController < ApplicationController
     if system_password
       # form submitted
       if wiki.authenticate(system_password)
-        wiki.edit_web(
-          @web.address, @params['address'], @params['name'], 
-          @params['markup'].intern, 
-          @params['color'], @params['additional_style'], 
-          @params['safe_mode'] ? true : false, 
-          @params['password'].empty? ? nil : @params['password'],
-          @params['published'] ? true : false, 
-          @params['brackets_only'] ? true : false,
-          @params['count_pages'] ? true : false,
-          @params['allow_uploads'] ? true : false,
-          @params['max_upload_size']
-        )
-        redirect_show('HomePage', @params['address'])
+        begin
+          wiki.edit_web(
+            @web.address, @params['address'], @params['name'], 
+            @params['markup'].intern, 
+            @params['color'], @params['additional_style'], 
+            @params['safe_mode'] ? true : false, 
+            @params['password'].empty? ? nil : @params['password'],
+            @params['published'] ? true : false, 
+            @params['brackets_only'] ? true : false,
+            @params['count_pages'] ? true : false,
+            @params['allow_uploads'] ? true : false,
+            @params['max_upload_size']
+          )
+          flash[:info] = "Web '#{@params['address']}' was successfully updated"
+          redirect_show('HomePage', @params['address'])
+        rescue Instiki::ValidationError => e
+          flash[:error] = e.message
+          # and re-render the same template again
+        end
       else
         flash[:error] = password_error(system_password)
         # and re-render the same template again
diff --git a/test/functional/admin_controller_test.rb b/test/functional/admin_controller_test.rb
index a829ca5b..3ca5ef85 100644
--- a/test/functional/admin_controller_test.rb
+++ b/test/functional/admin_controller_test.rb
@@ -164,6 +164,20 @@ class AdminControllerTest < Test::Unit::TestCase
     assert_flash_has :error
   end
 
+  def test_edit_web_rename_to_already_existing_web_name
+    @wiki.system[:password] = 'pswd'
+    
+    @wiki.create_web('Another', 'another')
+    process('edit_web', 'system_password' => 'pswd',
+      'web' => 'wiki1', 'address' => 'another', 'name' => 'Renamed Wiki1',
+      'markup' => 'markdown', 'color' => 'blue', 'additional_style' => 'whatever', 
+      'password' => 'new_password')
+      
+    #returns to the same form
+    assert_success
+    assert_flash_has :error
+  end
+
   def test_edit_web_empty_password
     process('edit_web', 'system_password' => '',
       'web' => 'wiki1', 'address' => 'renamed_wiki1', 'name' => 'Renamed Wiki1',