diff --git a/spec/controllers/assemblies_controller_spec.rb b/spec/controllers/assemblies_controller_spec.rb
index f28fd0e2c6..94d2a9fc7e 100644
--- a/spec/controllers/assemblies_controller_spec.rb
+++ b/spec/controllers/assemblies_controller_spec.rb
@@ -146,11 +146,12 @@ module Assemblies
         context "when sort_by_date variable is true" do
           before do
             allow(Rails.application.secrets).to receive(:dig).with(:decidim, :participatory_processes, :sort_by_date).and_return(true)
+            active_processes.first.update(end_date: nil)
           end
 
-          it "includes only participatory processes related to the assembly, actives one by end_date then upcoming ones by start_date then past ones by end_date reversed" do
+          it "includes only participatory processes related to the assembly, actives one by end_date with end_date nil last, then upcoming ones by start_date then past ones by end_date reversed" do
             sorted_participatory_processes = {
-              active: participatory_processes.select(&:active?).sort_by(&:end_date),
+              active: participatory_processes.reject { |process| process.end_date.nil? }.select(&:active?).sort_by(&:end_date) + participatory_processes.select { |process| process.end_date.nil? && process.active? },
               future: participatory_processes.select(&:upcoming?).sort_by(&:start_date),
               past: participatory_processes.select(&:past?).sort_by(&:end_date).reverse
             }
diff --git a/spec/controllers/participatory_processes_controller_spec.rb b/spec/controllers/participatory_processes_controller_spec.rb
index 52d34d206b..977ccc12b6 100644
--- a/spec/controllers/participatory_processes_controller_spec.rb
+++ b/spec/controllers/participatory_processes_controller_spec.rb
@@ -137,11 +137,12 @@ module ParticipatoryProcesses
           context "and sort_by_date is true" do
             before do
               allow(Rails.application.secrets).to receive(:dig).with(:decidim, :participatory_processes, :sort_by_date).and_return(true)
+              active_processes.first.update(end_date: nil)
             end
             # search.with_date will default to "active"
 
             it "orders active processes by end date" do
-              expect(controller.helpers.participatory_processes).to eq(active_processes.sort_by(&:end_date))
+              expect(controller.helpers.participatory_processes).to eq(active_processes.reject { |process| process.end_date.nil? }.sort_by(&:end_date) + active_processes.select { |process| process.end_date.nil? })
             end
           end
         end