diff --git a/app/views/evaluations/_exercises_progress_table.html.erb b/app/views/evaluations/_exercises_progress_table.html.erb
index 6b39092e29..e2e5bd23a3 100644
--- a/app/views/evaluations/_exercises_progress_table.html.erb
+++ b/app/views/evaluations/_exercises_progress_table.html.erb
@@ -50,7 +50,7 @@
           </a>
           <script>
             dodona.ready.then(() =>{
-              dodona.initDolosBtn('dolos-btn-<%= meta[:exercise].id %>', "<%= series_exports_path(@evaluation.series, token: (@evaluation.series.access_token if @evaluation.series.hidden?), selected_ids: [meta[:exercise].id], evaluation: true) %>", "<%= meta[:exercise].programming_language.renderer_name %>");
+              dodona.initDolosBtn('dolos-btn-<%= meta[:exercise].id %>', "<%= series_exports_path(@evaluation.series, token: (@evaluation.series.access_token if @evaluation.series.hidden?), selected_ids: [meta[:exercise].id], evaluation: true) %>", "<%= meta[:exercise].programming_language&.renderer_name %>");
             })
           </script>
         </td>
diff --git a/app/views/submissions/index.html.erb b/app/views/submissions/index.html.erb
index 131775a4db..dad0b08d61 100644
--- a/app/views/submissions/index.html.erb
+++ b/app/views/submissions/index.html.erb
@@ -52,7 +52,7 @@
             <% actions << {icon: 'graph-outline', text: t('.detect_plagiarism'), id: "dolos-btn" } if @series && @activity %>
             <script>
               dodona.ready.then(() => {
-                dodona.initDolosBtn("dolos-btn", "<%= series_exports_path(@series, token: (@series.access_token if @series.hidden?), selected_ids: [@activity.id]) %>", "<%= @activity.programming_language.renderer_name %>");
+                dodona.initDolosBtn("dolos-btn", "<%= series_exports_path(@series, token: (@series.access_token if @series.hidden?), selected_ids: [@activity.id]) %>", "<%= @activity.programming_language&.renderer_name %>");
               });
             </script>
           <% end %>