diff --git a/app/controllers/my_profile/profile_editor_controller.rb b/app/controllers/my_profile/profile_editor_controller.rb
index 2eb3014..62911e4 100644
--- a/app/controllers/my_profile/profile_editor_controller.rb
+++ b/app/controllers/my_profile/profile_editor_controller.rb
@@ -109,7 +109,7 @@ class ProfileEditorController < MyProfileController
       profile = environment.profiles.find(params[:id])
       if profile.disable
         profile.save
-        session[:notice] = _("The profile '#{profile.name}' was deactivated.")
+        session[:notice] = _("The profile '%s' was deactivated.") % profile.name
       else
         session[:notice] = _('Could not deactivate profile.')
       end
@@ -123,7 +123,7 @@ class ProfileEditorController < MyProfileController
       profile = environment.profiles.find(params[:id])
 
       if profile.enable
-        session[:notice] = _("The profile '#{profile.name}' was activated.")
+        session[:notice] = _("The profile '%s' was activated.") % profile.name
       else
         session[:notice] = _('Could not activate the profile.')
       end
diff --git a/app/views/content_viewer/article_versions.html.erb b/app/views/content_viewer/article_versions.html.erb
index b3b01ba..7e95e51 100644
--- a/app/views/content_viewer/article_versions.html.erb
+++ b/app/views/content_viewer/article_versions.html.erb
@@ -12,7 +12,7 @@
       <li>
         <%= radio_button_tag 'v1', v.version, false, :onclick => 'versionInputClicked(this)' %>
         <%= radio_button_tag 'v2', v.version, false, :onclick => 'versionInputClicked(this)' %>
-        <%= link_to(_("Version #{v.version}"), @page.url.merge(:version => v.version)) %>
+        <%= link_to(_("Version %s") % v.version, @page.url.merge(:version => v.version)) %>
         <%= @page.version == v.version ? _('(current)') : '' %>
         <span class='updated-by'><%= _('by %{author}') % {:author => link_to(@page.author_name(v.version), @page.author_url(v.version))} %></span>
         <span class='updated-on'><%= show_time(v.updated_at) %></span>
diff --git a/app/views/profile_roles/destroy.html.erb b/app/views/profile_roles/destroy.html.erb
index a790578..4e5384f 100644
--- a/app/views/profile_roles/destroy.html.erb
+++ b/app/views/profile_roles/destroy.html.erb
@@ -1,4 +1,4 @@
-<h1> <%= _("Deleting #{@role.name}") %> </h1>
+<h1> <%= _("Deleting %s") % @role.name %> </h1>
 
 <% if @members.nil? || @members.empty? %>
   <p><%= _('This role is not being currently used.')%></p>
diff --git a/app/views/profile_roles/edit.html.erb b/app/views/profile_roles/edit.html.erb
index 52b87aa..f91ec55 100644
--- a/app/views/profile_roles/edit.html.erb
+++ b/app/views/profile_roles/edit.html.erb
@@ -1,3 +1,3 @@
-<h1> <%= _("Editing #{@role.name}") %> </h1>
+<h1> <%= _("Editing %s") % @role.name %> </h1>
 
 <%= render :partial => 'form', :locals => { :mode => :edit, :role => @role, :permissions => [@role.kind] } %>
diff --git a/app/views/role/edit.html.erb b/app/views/role/edit.html.erb
index 8672e37..17aaf81 100644
--- a/app/views/role/edit.html.erb
+++ b/app/views/role/edit.html.erb
@@ -1,3 +1,3 @@
-<h2> <%= _("Editing #{@role.name}") %> </h2>
+<h2> <%= _("Editing %s") % @role.name %> </h2>
 
 <%= render :partial => 'form', :locals => { :mode => :edit, :role => @role, :permissions => role_available_permissions(@role) } %>
diff --git a/app/views/shared/_content_item.html.erb b/app/views/shared/_content_item.html.erb
index c8987d7..5c9dc24 100644
--- a/app/views/shared/_content_item.html.erb
+++ b/app/views/shared/_content_item.html.erb
@@ -6,6 +6,6 @@
     <span class="item-description">
       <%= link_to(content.name, content.url) %>
     </span>
-    <span class="item-date"><%= _("Published at: #{show_date(content.updated_at)}") %></span>
+    <span class="item-date"><%= _("Published at: %s") % show_date(content.updated_at) %></span>
   </div>
 </div>
diff --git a/lib/tasks/gettext.rake b/lib/tasks/gettext.rake
index 86f2375..d1d6bf3 100644
--- a/lib/tasks/gettext.rake
+++ b/lib/tasks/gettext.rake
@@ -60,6 +60,8 @@ task :updatepo do
 
   puts 'Extracting strings from source. This may take a while ...'
 
+  # XXX this list is duplicated in test/unit/i18n_test.rb; if you change it
+  # here, please also update it there.
   files_to_translate = [
     "{app,lib}/**/*.{rb,rhtml,erb}",
     'config/initializers/*.rb',
diff --git a/plugins/oauth_client/controllers/public/oauth_client_plugin_public_controller.rb b/plugins/oauth_client/controllers/public/oauth_client_plugin_public_controller.rb
index af11fc7..fcbe9fa 100644
--- a/plugins/oauth_client/controllers/public/oauth_client_plugin_public_controller.rb
+++ b/plugins/oauth_client/controllers/public/oauth_client_plugin_public_controller.rb
@@ -29,7 +29,7 @@ class OauthClientPluginPublicController < PublicController
     if user_provider.enabled? && provider.enabled?
       session[:user] = user.id
     else
-      session[:notice] = _("Can't login with #{provider.name}")
+      session[:notice] = _("Can't login with %s") % provider.name
     end
 
     redirect_to :controller => :account, :action => :login
diff --git a/plugins/oauth_provider/views/doorkeeper/authorizations/new.html.erb b/plugins/oauth_provider/views/doorkeeper/authorizations/new.html.erb
index 9326365..2c6455c 100644
--- a/plugins/oauth_provider/views/doorkeeper/authorizations/new.html.erb
+++ b/plugins/oauth_provider/views/doorkeeper/authorizations/new.html.erb
@@ -6,7 +6,7 @@
 
 <main role="main">
   <p class="h4">
-  <%= _('Authorize %s to use your account?' % "<strong class=\"text-info\">#{@pre_auth.client.name}</strong>") %>
+  <%= _('Authorize %s to use your account?') % "<strong class=\"text-info\">#{@pre_auth.client.name}</strong>" %>
   </p>
 
   <% if @pre_auth.scopes %>
diff --git a/plugins/sub_organizations/lib/related_organizations_block.rb b/plugins/sub_organizations/lib/related_organizations_block.rb
index 16dff0d..7222c69 100644
--- a/plugins/sub_organizations/lib/related_organizations_block.rb
+++ b/plugins/sub_organizations/lib/related_organizations_block.rb
@@ -24,7 +24,7 @@ class RelatedOrganizationsBlock < ProfileListBlock
   end
 
   def help
-    _("This block displays #{display_type[:title]} organizations of this organization")
+    _("This block displays %s organizations of this organization") % display_type[:title]
   end
 
   def profiles
diff --git a/plugins/sub_organizations/views/sub_organizations_plugin_profile/_full_related_organizations.html.erb b/plugins/sub_organizations/views/sub_organizations_plugin_profile/_full_related_organizations.html.erb
index 6bac536..a956d6e 100644
--- a/plugins/sub_organizations/views/sub_organizations_plugin_profile/_full_related_organizations.html.erb
+++ b/plugins/sub_organizations/views/sub_organizations_plugin_profile/_full_related_organizations.html.erb
@@ -1,7 +1,7 @@
 <% extend SubOrganizationsPlugin::SearchHelper %>
 <div class="related-organizations-list-block">
 
-  <h1><%= _("#{profile.name}'s sub-#{organization_type.pluralize}") %></h1>
+  <h1><%= _("%s's sub-%s") % [profile.name, organization_type.pluralize] %></h1>
   <ul>
   <% organizations.each do |organization| %>
     <li class="related-organizations-item">
@@ -53,7 +53,7 @@
 
   <% button_bar(:class => "related-organizations-button-bar") do %>
     <%= button :back, c_('Go back'), { :controller => 'profile' } %>
-    <%= button :add, _("Add a new #{organization_type}"), :controller => 'sub_organizations_plugin_myprofile', :action => 'index' if logged_in? && user.has_permission?(:edit_profile, profile) && !environment.enabled?("disable_asset_#{organization_type.pluralize}") %>
+    <%= button :add, _("Add a new %s") % organization_type, :controller => 'sub_organizations_plugin_myprofile', :action => 'index' if logged_in? && user.has_permission?(:edit_profile, profile) && !environment.enabled?("disable_asset_#{organization_type.pluralize}") %>
 
     <% if !@full %>
       <%= button :more, c_('View all'), { :controller => 'sub_organizations_plugin_profile', :action => params[:action], :type => organization_type } %>
diff --git a/plugins/sub_organizations/views/sub_organizations_plugin_profile/_related_organizations.html.erb b/plugins/sub_organizations/views/sub_organizations_plugin_profile/_related_organizations.html.erb
index a27823a..cd0728f 100644
--- a/plugins/sub_organizations/views/sub_organizations_plugin_profile/_related_organizations.html.erb
+++ b/plugins/sub_organizations/views/sub_organizations_plugin_profile/_related_organizations.html.erb
@@ -1,5 +1,5 @@
 <div class="common-profile-list-block">
-  <h1><%= _("#{profile.name}'s sub-#{organization_type.pluralize}") %></h1>
+  <h1><%= _("%s's sub-%s") % [profile.name, organization_type.pluralize] %></h1>
 
   <ul class='profile-list'>
     <% organizations.each do |organization| %>
@@ -7,11 +7,11 @@
     <% end %>
   </ul>
   <% if organizations.length == 0 %>
-    <li><%= _("There are no sub-#{organization_type.pluralize} yet. " )  %></li>
+    <li><%= _("There are no sub-%s yet.")  % organization_type.pluralize %></li>
   <% end %>
   <% button_bar(:class => "related-organizations-button-bar") do %>
     <%= button :back, c_('Go back'), { :controller => 'profile' } %>
-    <%= button :add, _("Add a new #{organization_type}"), :controller => 'sub_organizations_plugin_myprofile', :action => 'index' if logged_in? && user.has_permission?(:edit_profile, profile) && !environment.enabled?("disable_asset_#{organization_type.pluralize}") %>
+    <%= button :add, _("Add a new %s") % organization_type, :controller => 'sub_organizations_plugin_myprofile', :action => 'index' if logged_in? && user.has_permission?(:edit_profile, profile) && !environment.enabled?("disable_asset_#{organization_type.pluralize}") %>
 
     <% if !@full %>
       <%= button :more, c_('View all'), { :controller => 'sub_organizations_plugin_profile', :action => params[:action], :type => organization_type } %>
diff --git a/test/unit/i18n_test.rb b/test/unit/i18n_test.rb
new file mode 100644
index 0000000..9802255
--- /dev/null
+++ b/test/unit/i18n_test.rb
@@ -0,0 +1,25 @@
+require_relative "../test_helper"
+
+class I18nTest < ActiveSupport::TestCase
+
+  # XXX this duplicates the list from lib/tasks/gettext.rake
+  files_to_translate = [
+    "{app,lib}/**/*.{rb,rhtml,erb}",
+    'config/initializers/*.rb',
+    'public/*.html.erb',
+    'public/designs/themes/{base,noosfero,profile-base}/*.{rhtml,html.erb}',
+  ].map { |pattern| Dir.glob(pattern) }.flatten
+
+  plugins_files_to_translate = Dir.glob("plugins/**/*.{rb,html.erb}")
+
+  (files_to_translate + plugins_files_to_translate).each do |f|
+    test "translation marks in #{f}" do
+      lines = File.readlines(f).select do |line|
+        line =~ /\b_\(["'][^)]*#\{/
+      end
+      assert lines == [], "found interpolation in translatable strings:\n" + lines.join("\n")
+    end
+  end
+
+end
+
--
libgit2 0.21.2