diff --git a/app/controllers/decidim/assemblies/assemblies_controller.rb b/app/controllers/decidim/assemblies/assemblies_controller.rb
index 6fa700f10d..c409bde9a2 100644
--- a/app/controllers/decidim/assemblies/assemblies_controller.rb
+++ b/app/controllers/decidim/assemblies/assemblies_controller.rb
@@ -89,10 +89,11 @@ def assembly_participatory_processes
           @assembly_participatory_processes ||= @current_participatory_space.linked_participatory_space_resources(:participatory_processes, "included_participatory_processes")
         else
           @assembly_participatory_processes = @current_participatory_space.linked_participatory_space_resources(:participatory_processes, "included_participatory_processes")
+          @active_processes ||= @assembly_participatory_processes.select(&:active?)
           sorted_by_date = {
-            active: @assembly_participatory_processes.active_spaces.sort_by(&:end_date),
-            future: @assembly_participatory_processes.future_spaces.sort_by(&:start_date),
-            past: @assembly_participatory_processes.past_spaces.sort_by(&:end_date).reverse
+            active: @active_processes.reject { |process| process.end_date.nil? }.sort_by(&:end_date) + processes_without_end_date(@active_processes),
+            future: @assembly_participatory_processes.upcoming.sort_by(&:start_date),
+            past: @assembly_participatory_processes.past.sort_by(&:end_date).reverse
           }
           @assembly_participatory_processes = sorted_by_date
         end
@@ -101,6 +102,10 @@ def assembly_participatory_processes
       def current_assemblies_settings
         @current_assemblies_settings ||= Decidim::AssembliesSetting.find_or_create_by(decidim_organization_id: current_organization.id)
       end
+
+      def processes_without_end_date(processes)
+        processes.select { |process| process.end_date.nil? }
+      end
     end
   end
 end
diff --git a/app/controllers/decidim/participatory_processes/participatory_processes_controller.rb b/app/controllers/decidim/participatory_processes/participatory_processes_controller.rb
index e1d755b7a3..72b7cf0f25 100644
--- a/app/controllers/decidim/participatory_processes/participatory_processes_controller.rb
+++ b/app/controllers/decidim/participatory_processes/participatory_processes_controller.rb
@@ -136,7 +136,7 @@ def linked_assemblies
       def custom_sort(date)
         case date
         when "active"
-          @participatory_processes.sort_by(&:end_date)
+          @participatory_processes.reject { |process| process.end_date.nil? }.sort_by(&:end_date) + processes_without_end_date(@participatory_processes)
         when "past"
           @participatory_processes.sort_by(&:end_date).reverse
         when "upcoming"
@@ -149,11 +149,16 @@ def custom_sort(date)
       end
 
       def sort_all_processes
-        actives = @participatory_processes.select(&:active?).sort_by(&:end_date)
+        @actives_processes ||= @participatory_processes.select(&:active?)
+        actives = @actives_processes.reject { |process| process.end_date.nil? }.sort_by(&:end_date) + processes_without_end_date(@actives_processes)
         pasts = @participatory_processes.select(&:past?).sort_by(&:end_date).reverse
         upcomings = @participatory_processes.select(&:upcoming?).sort_by(&:start_date)
         (actives + upcomings + pasts)
       end
+
+      def processes_without_end_date(processes)
+        processes.select { |process| process.end_date.nil? }
+      end
     end
   end
 end
diff --git a/spec/controllers/assemblies_controller_spec.rb b/spec/controllers/assemblies_controller_spec.rb
index f28fd0e2c6..5d90dee6a5 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.select { |process| process.active? && !process.end_date.nil? }.sort_by(&:end_date) + participatory_processes.select { |process| process.active? && process.end_date.nil? },
               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