diff --git a/vedia.rb b/vedia.rb
index ee3ec7b..54c3d70 100644
--- a/vedia.rb
+++ b/vedia.rb
@@ -11,6 +11,7 @@ require 'gettext'
 require 'securerandom'
 require 'chartkick'
 require 'mail'
+require 'ostruct'
 require 'tzinfo'
 require 'redcarpet'
 
@@ -386,16 +387,31 @@ post '/votes/:id/reopen' do
   redirect '/votes/' + @vote.secure_id
 end
 
+get '/votes/:id/ratings' do
+  redirect '/votes/' + params[:id]
+end
+
 post '/votes/:id/ratings' do
   require_login
   find_vote
   require_open_vote
+  @errors = []
   @vote.candidates.each do |candidate|
-    rating = Rating.find_or_initialize_by(vote: @vote, user: current_user, candidate: candidate)
-    rating.value = params[candidate.id.to_s]
-    rating.save
+    if not params[candidate.id.to_s]
+      @errors << OpenStruct.new(:attribute => :rating, :type => :blank, :candidate => candidate)
+    end
+  end
+  if not @errors.empty?
+    @params = params
+    erb :votes_show_open
+  else
+    @vote.candidates.each do |candidate|
+      rating = Rating.find_or_initialize_by(vote: @vote, user: current_user, candidate: candidate)
+      rating.value = params[candidate.id.to_s]
+      rating.save
+    end
+    redirect '/votes/' + @vote.secure_id
   end
-  redirect '/votes/' + @vote.secure_id
 end
 
 post '/votes/:id/organizers' do
diff --git a/views/votes_show_open.erb b/views/votes_show_open.erb
index d5f5a8f..757afb5 100644
--- a/views/votes_show_open.erb
+++ b/views/votes_show_open.erb
@@ -1,5 +1,13 @@
 <h1><%= @vote.title %></h1>
 
+<% if @errors %>
+<% @errors.each do |error| %>
+  <% if error.attribute == :rating and error.type == :blank %>
+  <p class="error"><%= _("Missing rating for candidate <i>%{name}</i>." % { name: error.candidate.name }) %></p>
+  <% end %>
+<% end %>
+<% end %>
+
 <% if @vote.expire_on %>
 <p><%= _("Closing date: %{date}" % { date: format_date_and_time(@vote.expire_on) }) %></p>
 <% end %>
@@ -12,7 +20,13 @@
 <ul>
   <% @vote.candidates.each do |candidate| %>
   <% rating = @vote.ratings.find { |rating| rating.user == current_user and rating.candidate == candidate } %>
-  <% value = rating ? rating.value : 0 %>
+  <% if rating
+       value = rating.value
+     elsif @params[candidate.id.to_s]
+       value = params[candidate.id.to_s].to_i
+     else
+       value = 0
+     end %>
   <li>
     <p><b><%= candidate.name %></b></p>
     <%= markdown(candidate.description) %>