diff --git a/app/models/journal/caused_by_system_update.rb b/app/models/journal/caused_by_system_update.rb
index 5cceaec9c6d..5ec71544f82 100644
--- a/app/models/journal/caused_by_system_update.rb
+++ b/app/models/journal/caused_by_system_update.rb
@@ -29,10 +29,9 @@
 #++
 #
 class Journal::CausedBySystemUpdate < CauseOfChange::Base
-  def initialize(feature:)
-    additional = {
-      "feature" => feature
-    }
-    super("system_update", additional)
+  def initialize(feature:, **additional_attributes)
+    system_update_attributes =
+      { "feature" => feature }.merge(additional_attributes.deep_stringify_keys)
+    super("system_update", system_update_attributes)
   end
 end
diff --git a/config/locales/en.yml b/config/locales/en.yml
index 156f16a10c5..d667d4ec16b 100644
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@@ -3449,6 +3449,7 @@ en:
         totals_removed_from_childless_work_packages: >-
           Work and progress totals automatically removed for non-parent work packages with <a href="%{href}" target="_blank">version update</a>.
           This is a maintenance task and can be safely ignored.
+        sprint_migration: "Version '%{version_name}' has been converted to a Sprint."
       total_percent_complete_mode_changed_to_work_weighted_average: >-
         Child work packages without Work are ignored.
       total_percent_complete_mode_changed_to_simple_average: >-
diff --git a/lib/open_project/journal_formatter/cause.rb b/lib/open_project/journal_formatter/cause.rb
index 7170681b76b..3c708bafb5d 100644
--- a/lib/open_project/journal_formatter/cause.rb
+++ b/lib/open_project/journal_formatter/cause.rb
@@ -101,6 +101,8 @@ class OpenProject::JournalFormatter::Cause < JournalFormatter::Base
         { href: OpenProject::Static::Links.url_for(:blog_article_progress_changes) }
       when "totals_removed_from_childless_work_packages"
         { href: OpenProject::Static::Links.url_for(:release_notes_14_0_1) }
+      when "sprint_migration"
+        { version_name: cause["version_name"] }
       else
         {}
       end
diff --git a/modules/backlogs/app/models/agile/sprint.rb b/modules/backlogs/app/models/agile/sprint.rb
index cef4d7f6f34..d08bfde9f5e 100644
--- a/modules/backlogs/app/models/agile/sprint.rb
+++ b/modules/backlogs/app/models/agile/sprint.rb
@@ -54,13 +54,11 @@ module Agile
          default: "in_planning",
          validate: true
 
-    validates :name, presence: true
-    validates :project, presence: true
-    validates :start_date, presence: true
-    validates :finish_date, presence: true
+    validates :name, :project, presence: true
+    validates :start_date, :finish_date, presence: true, if: :active?
     validates :finish_date,
               comparison: { greater_than_or_equal_to: :start_date },
-              if: :start_date?
+              if: -> { start_date? && finish_date? }
 
     validate :validate_only_one_active_sprint_per_project
 
diff --git a/modules/backlogs/app/workers/backlogs/migrate_version_sprint_journals_job.rb b/modules/backlogs/app/workers/backlogs/migrate_version_sprint_journals_job.rb
new file mode 100644
index 00000000000..0f05964c337
--- /dev/null
+++ b/modules/backlogs/app/workers/backlogs/migrate_version_sprint_journals_job.rb
@@ -0,0 +1,55 @@
+# frozen_string_literal: true
+
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See COPYRIGHT and LICENSE files for more details.
+#++
+
+# Writes a journal entry on each work package that was associated with a sprint
+# during the version-to-sprint migration. Runs asynchronously after the migration
+# so that the migration itself does not block on journal creation.
+module Backlogs
+  class MigrateVersionSprintJournalsJob < ApplicationJob
+    # wp_version_map: { work_package_id (Integer) => version_name (String) }
+    def perform(wp_version_map)
+      system_user = User.system
+
+      work_packages = WorkPackage.where(id: wp_version_map.keys).index_by(&:id)
+
+      Journal::NotificationConfiguration.with(false) do
+        wp_version_map.each do |wp_id_str, version_name|
+          wp_id = wp_id_str.to_i
+          work_package = work_packages[wp_id]
+          next unless work_package
+
+          Journals::CreateService
+            .new(work_package, system_user)
+            .call(cause: Journal::CausedBySystemUpdate.new(feature: "sprint_migration", version_name:))
+        end
+      end
+    end
+  end
+end
diff --git a/modules/backlogs/db/migrate/20260313163122_make_sprint_dates_nullable.rb b/modules/backlogs/db/migrate/20260313163122_make_sprint_dates_nullable.rb
new file mode 100644
index 00000000000..1b270cbcbcb
--- /dev/null
+++ b/modules/backlogs/db/migrate/20260313163122_make_sprint_dates_nullable.rb
@@ -0,0 +1,36 @@
+# frozen_string_literal: true
+
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See COPYRIGHT and LICENSE files for more details.
+#++
+
+class MakeSprintDatesNullable < ActiveRecord::Migration[8.0]
+  def change
+    change_column_null :sprints, :start_date, true
+    change_column_null :sprints, :finish_date, true
+  end
+end
diff --git a/modules/backlogs/db/migrate/20260313164539_migrate_versions_to_sprints.rb b/modules/backlogs/db/migrate/20260313164539_migrate_versions_to_sprints.rb
new file mode 100644
index 00000000000..b20959f764f
--- /dev/null
+++ b/modules/backlogs/db/migrate/20260313164539_migrate_versions_to_sprints.rb
@@ -0,0 +1,76 @@
+# frozen_string_literal: true
+
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See COPYRIGHT and LICENSE files for more details.
+#++
+
+class MigrateVersionsToSprints < ActiveRecord::Migration[8.0]
+  def up
+    wp_version_map = {}
+
+    sprint_versions_with_work_package_ids.each do |version, wp_ids|
+      sprint = create_sprint(version)
+      migrate_work_packages_to_sprint(sprint, wp_ids)
+      wp_ids.each { |wp_id| wp_version_map[wp_id.to_s] = sprint.name }
+    end
+
+    Backlogs::MigrateVersionSprintJournalsJob.perform_later(wp_version_map) if wp_version_map.any?
+  end
+
+  def down
+    raise ActiveRecord::IrreversibleMigration
+  end
+
+  private
+
+  def sprint_versions_with_work_package_ids
+    # Load versions used as sprints including work package ids associated with the version.
+    # Since the same version can be used as a sprint in one project but not in another,
+    # the work package ids are filtered by projects where the version is used as a sprint.
+    Version.joins(:version_settings, :work_packages)
+           .where(version_settings: { display: VersionSetting::DISPLAY_LEFT })
+           .where("work_packages.project_id = version_settings.project_id")
+           .includes(:project)
+           .group("versions.id")
+           .select("versions.*, array_agg(work_packages.id) AS wp_ids")
+           .map { |version| [version, version.wp_ids] }
+  end
+
+  def create_sprint(version)
+    Agile::Sprint.create!(
+      name: version.name,
+      project: version.project,
+      status: version.status == "open" ? "in_planning" : "completed",
+      start_date: version.start_date,
+      finish_date: version.effective_date
+    )
+  end
+
+  def migrate_work_packages_to_sprint(sprint, wp_ids)
+    WorkPackage.where(id: wp_ids).update_all(sprint_id: sprint.id)
+  end
+end
diff --git a/modules/backlogs/spec/contracts/sprints/create_contract_spec.rb b/modules/backlogs/spec/contracts/sprints/create_contract_spec.rb
index f542fac55b7..48b84dd1267 100644
--- a/modules/backlogs/spec/contracts/sprints/create_contract_spec.rb
+++ b/modules/backlogs/spec/contracts/sprints/create_contract_spec.rb
@@ -89,13 +89,13 @@ RSpec.describe Sprints::CreateContract do
     context "when start_date is blank" do
       let(:sprint_start_date) { nil }
 
-      it_behaves_like "contract is invalid", start_date: :blank
+      it_behaves_like "contract is valid"
     end
 
     context "when finish_date is blank" do
       let(:sprint_finish_date) { nil }
 
-      it_behaves_like "contract is invalid", finish_date: %i[blank blank]
+      it_behaves_like "contract is valid"
     end
 
     context "when finish_date is before start_date" do
@@ -105,6 +105,29 @@ RSpec.describe Sprints::CreateContract do
       it_behaves_like "contract is invalid", finish_date: %i[greater_than_or_equal_to]
     end
 
+    context "when the sprint is active" do
+      let(:sprint_status) { "active" }
+
+      context "when start_date is blank" do
+        let(:sprint_start_date) { nil }
+
+        it_behaves_like "contract is invalid", start_date: :blank
+      end
+
+      context "when finish_date is blank" do
+        let(:sprint_finish_date) { nil }
+
+        it_behaves_like "contract is invalid", finish_date: :blank
+      end
+
+      context "when finish_date is before start_date" do
+        let(:sprint_start_date) { Time.zone.today }
+        let(:sprint_finish_date) { Time.zone.today - 1.day }
+
+        it_behaves_like "contract is invalid", finish_date: %i[greater_than_or_equal_to]
+      end
+    end
+
     context "when user is admin without project permission" do
       let(:user) { build_stubbed(:admin) }
       let(:permissions) { [] }
diff --git a/modules/backlogs/spec/features/sprints/create_spec.rb b/modules/backlogs/spec/features/sprints/create_spec.rb
index 3bc70e498be..f3e484ee720 100644
--- a/modules/backlogs/spec/features/sprints/create_spec.rb
+++ b/modules/backlogs/spec/features/sprints/create_spec.rb
@@ -121,20 +121,6 @@ RSpec.describe "Create", :js do
       describe "validations" do
         let(:too_early_finish_date) { start_date - 1.day }
 
-        it "validates required fields are present" do
-          backlogs_page.open_create_sprint_dialog
-
-          within_dialog "New sprint" do
-            page.fill_in "Sprint name", with: ""
-
-            click_on "Create"
-
-            expect(page).to have_field "Sprint name", validation_error: "can't be blank"
-            expect(page).to have_field "Start date", validation_error: "can't be blank"
-            expect(page).to have_field "Finish date", validation_error: "can't be blank"
-          end
-        end
-
         it "validates finish date is not before start date" do
           backlogs_page.open_create_sprint_dialog
 
diff --git a/modules/backlogs/spec/features/sprints/edit_spec.rb b/modules/backlogs/spec/features/sprints/edit_spec.rb
index 8e49b34ddbd..442f6262c68 100644
--- a/modules/backlogs/spec/features/sprints/edit_spec.rb
+++ b/modules/backlogs/spec/features/sprints/edit_spec.rb
@@ -162,6 +162,29 @@ RSpec.describe "Edit", :js do
             end
           end
         end
+
+        describe "validations" do
+          context "when sprint status is active" do
+            before { first_sprint.update!(status: "active") }
+
+            it "validates required fields are present" do
+              backlogs_page.click_in_sprint_menu(first_sprint, "Edit sprint")
+              backlogs_page.expect_sprint_dialog
+
+              within_dialog "Edit sprint" do
+                page.fill_in "Sprint name", with: ""
+                page.fill_in "Start date", with: ""
+                page.fill_in "Finish date", with: ""
+
+                page.click_button "Save"
+
+                expect(page).to have_field "Sprint name", validation_error: "can't be blank"
+                expect(page).to have_field "Start date", validation_error: "can't be blank"
+                expect(page).to have_field "Finish date", validation_error: "can't be blank"
+              end
+            end
+          end
+        end
       end
     end
 
diff --git a/modules/backlogs/spec/migrations/migrate_versions_to_sprints_spec.rb b/modules/backlogs/spec/migrations/migrate_versions_to_sprints_spec.rb
new file mode 100644
index 00000000000..ca7085207ff
--- /dev/null
+++ b/modules/backlogs/spec/migrations/migrate_versions_to_sprints_spec.rb
@@ -0,0 +1,209 @@
+# frozen_string_literal: true
+
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See COPYRIGHT and LICENSE files for more details.
+#++
+
+require "spec_helper"
+require Rails.root.join("modules/backlogs/db/migrate/20260313164539_migrate_versions_to_sprints")
+
+RSpec.describe MigrateVersionsToSprints, type: :model do
+  subject(:migrate) { ActiveRecord::Migration.suppress_messages { described_class.migrate(:up) } }
+
+  let(:project) { create(:project) }
+  let(:start_date) { nil }
+  let(:effective_date) { nil }
+  let(:status) { "open" }
+  let(:version_type) { :sprint }
+  let!(:version) do
+    create(:version, project:, name: "Test Sprint", start_date:, effective_date:, status:)
+  end
+  let!(:wp1) { create(:work_package, version:, project:) }
+
+  def use_version(as:, version: self.version, project: self.project)
+    display = as == :sprint ? VersionSetting::DISPLAY_LEFT : VersionSetting::DISPLAY_RIGHT
+    create(:version_setting, version:, project:, display:)
+  end
+
+  before { use_version(as: version_type) }
+
+  describe "qualification criteria" do
+    context "when all criteria are met (used as sprint and work package present)" do
+      let(:start_date)     { Date.new(2026, 1, 1) }
+      let(:effective_date) { Date.new(2026, 1, 14) }
+
+      it "creates one sprint" do
+        expect { migrate }.to change(Agile::Sprint, :count).by(1)
+      end
+
+      it "copies name, start_date and finish_date" do
+        migrate
+        sprint = Agile::Sprint.last
+        expect(sprint.name).to eq("Test Sprint")
+        expect(sprint.start_date).to eq(Date.new(2026, 1, 1))
+        expect(sprint.finish_date).to eq(Date.new(2026, 1, 14))
+      end
+    end
+
+    context "when version is used as a backlog" do
+      let(:version_type) { :backlog }
+
+      it "does not create a sprint" do
+        expect { migrate }.not_to change(Agile::Sprint, :count)
+      end
+    end
+
+    context "when no work packages are associated with the version" do
+      let!(:wp1) { nil }
+
+      it "does not create a sprint" do
+        expect { migrate }.not_to change(Agile::Sprint, :count)
+      end
+    end
+  end
+
+  describe "date handling" do
+    context "when both start_date and effective_date are null" do
+      it "creates a sprint with nil dates" do
+        expect { migrate }.to change(Agile::Sprint, :count).by(1)
+        sprint = Agile::Sprint.last
+        expect(sprint.start_date).to be_nil
+        expect(sprint.finish_date).to be_nil
+      end
+    end
+
+    context "when only effective_date is set" do
+      let(:effective_date) { Date.new(2026, 2, 28) }
+
+      it "sets effective_date for finish_date" do
+        migrate
+        sprint = Agile::Sprint.last
+        expect(sprint.start_date).to be_nil
+        expect(sprint.finish_date).to eq(Date.new(2026, 2, 28))
+      end
+    end
+
+    context "when only start_date is set" do
+      let(:start_date) { Date.new(2026, 2, 1) }
+
+      it "sets start_date for start_date" do
+        migrate
+        sprint = Agile::Sprint.last
+        expect(sprint.start_date).to eq(Date.new(2026, 2, 1))
+        expect(sprint.finish_date).to be_nil
+      end
+    end
+  end
+
+  describe "status mapping" do
+    context "when version status is open" do
+      let(:status) { "open" }
+
+      it "creates sprint with in_planning status" do
+        migrate
+        expect(Agile::Sprint.last.status).to eq("in_planning")
+      end
+    end
+
+    context "when version status is locked" do
+      let(:status) { "locked" }
+
+      it "creates sprint with completed status" do
+        migrate
+        expect(Agile::Sprint.last.status).to eq("completed")
+      end
+    end
+
+    context "when version status is closed" do
+      let(:status) { "closed" }
+
+      it "creates sprint with completed status" do
+        migrate
+        expect(Agile::Sprint.last.status).to eq("completed")
+      end
+    end
+  end
+
+  describe "work package association" do
+    let!(:wp2) { create(:work_package, version:, project:) }
+
+    it "sets sprint_id on all associated work packages" do
+      migrate
+      sprint = Agile::Sprint.last
+      expect(wp1.reload.sprint_id).to eq(sprint.id)
+      expect(wp2.reload.sprint_id).to eq(sprint.id)
+    end
+
+    it "keeps the version_id on associated work packages" do
+      migrate
+      expect(wp1.reload.version_id).to eq(version.id)
+      expect(wp2.reload.version_id).to eq(version.id)
+    end
+
+    context "with multiple versions" do
+      let!(:version2) { create(:version, project:, status: "closed") }
+      let!(:wp3) { create(:work_package, version: version2, project:) }
+
+      before { use_version(as: :sprint, version: version2) }
+
+      it "assigns work packages to their respective sprints" do
+        migrate
+        sprints = Agile::Sprint.all.index_by(&:name)
+        expect(wp1.reload.sprint_id).to eq(sprints[version.name].id)
+        expect(wp2.reload.sprint_id).to eq(sprints[version.name].id)
+        expect(wp3.reload.sprint_id).to eq(sprints[version2.name].id)
+      end
+    end
+
+    context "when the version is shared with another project that displays it as non-sprint" do
+      let(:other_project) { create(:project) }
+      let!(:wp_in_other_project) { create(:work_package, version:, project: other_project) }
+
+      before { use_version(as: :backlog, project: other_project) }
+
+      it "only assigns work packages from the sprint project" do
+        migrate
+        sprint = Agile::Sprint.last
+        expect(wp1.reload.sprint_id).to eq(sprint.id)
+        expect(wp2.reload.sprint_id).to eq(sprint.id)
+        expect(wp_in_other_project.reload.sprint_id).to be_nil
+      end
+    end
+  end
+
+  describe "journal job" do
+    it "enqueues MigrateVersionSprintJournalsJob with the work package mapping" do
+      allow(Backlogs::MigrateVersionSprintJournalsJob).to receive(:perform_later)
+
+      migrate
+
+      expect(Backlogs::MigrateVersionSprintJournalsJob)
+        .to have_received(:perform_later)
+        .with({ wp1.id.to_s => "Test Sprint" })
+    end
+  end
+end
diff --git a/modules/backlogs/spec/models/agile/sprint_spec.rb b/modules/backlogs/spec/models/agile/sprint_spec.rb
index 5ce79972dea..2063cf2c23e 100644
--- a/modules/backlogs/spec/models/agile/sprint_spec.rb
+++ b/modules/backlogs/spec/models/agile/sprint_spec.rb
@@ -32,51 +32,66 @@ require "spec_helper"
 
 RSpec.describe Agile::Sprint do
   let(:project) { create(:project) }
+  let(:sprint_status) { "in_planning" }
 
   subject(:sprint) do
     described_class.new(name: "Sprint 1",
                         project:,
                         start_date: Time.zone.today,
-                        finish_date: Time.zone.today + 14.days)
+                        finish_date: Time.zone.today + 14.days,
+                        status: sprint_status)
   end
 
   describe "validations" do
     it { is_expected.to validate_presence_of(:name) }
-    it { is_expected.to validate_presence_of(:start_date) }
-    it { is_expected.to validate_presence_of(:finish_date) }
     it { is_expected.to validate_presence_of(:project) }
     it { is_expected.to validate_inclusion_of(:status).in_array(described_class.statuses.keys) }
 
-    it "validates finish_date is after or equal to start_date" do
-      sprint.finish_date = sprint.start_date - 1.day
-      expect(sprint).not_to be_valid
-      expect(sprint.errors[:finish_date]).to include(/must be greater than or equal to/)
-    end
-
-    it "does not validate finish_date comparison when start_date is nil" do
-      sprint.start_date = nil
-      sprint.finish_date = Time.zone.today
-      expect(sprint).not_to be_valid
-      expect(sprint.errors[:start_date]).to be_present
-      expect(sprint.errors[:finish_date]).not_to include(/must be greater than or equal to/)
-    end
-
-    it "still validates finish_date presence even when start_date is nil" do
+    it "allows nil start and finish dates" do
       sprint.start_date = nil
       sprint.finish_date = nil
-      expect(sprint).not_to be_valid
-      expect(sprint.errors[:finish_date]).to be_present
+      expect(sprint).to be_valid
+    end
+
+    it "allows a nil finish date when start date is present" do
+      sprint.start_date = Time.zone.today
+      sprint.finish_date = nil
+      expect(sprint).to be_valid
     end
 
     context "with active sprint validation" do
+      let(:sprint_status) { "active" }
+
+      it { is_expected.to validate_presence_of(:start_date) }
+      it { is_expected.to validate_presence_of(:finish_date) }
+
+      it "validates finish_date is after or equal to start_date" do
+        sprint.finish_date = sprint.start_date - 1.day
+        expect(sprint).not_to be_valid
+        expect(sprint.errors[:finish_date]).to include(/must be greater than or equal to/)
+      end
+
+      it "does not validate finish_date comparison when start_date is nil" do
+        sprint.start_date = nil
+        sprint.finish_date = Time.zone.today
+        expect(sprint).not_to be_valid
+        expect(sprint.errors[:start_date]).to be_present
+        expect(sprint.errors[:finish_date]).not_to include(/must be greater than or equal to/)
+      end
+
+      it "still validates finish_date presence even when start_date is nil" do
+        sprint.start_date = nil
+        sprint.finish_date = nil
+        expect(sprint).not_to be_valid
+        expect(sprint.errors[:finish_date]).to be_present
+      end
+
       it "allows one active sprint per project" do
-        sprint.status = "active"
         expect(sprint).to be_valid
       end
 
       it "prevents multiple active sprints in the same project" do
         create(:agile_sprint, project:, status: "active")
-        sprint.status = "active"
         expect(sprint).not_to be_valid
         expect(sprint.errors[:status]).to include("only one active sprint is allowed per project.")
       end
@@ -84,12 +99,10 @@ RSpec.describe Agile::Sprint do
       it "allows multiple active sprints in different projects" do
         other_project = create(:project)
         create(:agile_sprint, project: other_project, status: "active")
-        sprint.status = "active"
         expect(sprint).to be_valid
       end
 
       it "allows updating an existing active sprint" do
-        sprint.status = "active"
         sprint.save!
         sprint.name = "Updated Sprint"
         expect(sprint).to be_valid
diff --git a/modules/backlogs/spec/workers/backlogs/migrate_version_sprint_journals_job_spec.rb b/modules/backlogs/spec/workers/backlogs/migrate_version_sprint_journals_job_spec.rb
new file mode 100644
index 00000000000..e4a3543b0e6
--- /dev/null
+++ b/modules/backlogs/spec/workers/backlogs/migrate_version_sprint_journals_job_spec.rb
@@ -0,0 +1,94 @@
+# frozen_string_literal: true
+
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See COPYRIGHT and LICENSE files for more details.
+#++
+
+require "spec_helper"
+
+RSpec.describe Backlogs::MigrateVersionSprintJournalsJob, type: :model do
+  let(:project) { create(:project) }
+  let(:wp1) { create(:work_package, project:) }
+  let(:wp2) { create(:work_package, project:) }
+
+  subject(:perform) { described_class.new.perform(wp_version_map) }
+
+  describe "#perform" do
+    context "with multiple work packages" do
+      let(:wp_version_map) do
+        {
+          wp1.id.to_s => "Sprint A",
+          wp2.id.to_s => "Sprint B"
+        }
+      end
+
+      it "creates a journal entry for each work package authored by the system user" do
+        perform
+        expect(wp1.reload.last_journal.user).to eq(User.system)
+        expect(wp2.reload.last_journal.user).to eq(User.system)
+      end
+
+      it "sets the cause type to system_update" do
+        perform
+        expect(wp1.reload.last_journal.cause_type).to eq("system_update")
+        expect(wp2.reload.last_journal.cause_type).to eq("system_update")
+      end
+
+      it "sets the cause feature to sprint_migration" do
+        perform
+        expect(wp1.reload.last_journal.cause_feature).to eq("sprint_migration")
+        expect(wp2.reload.last_journal.cause_feature).to eq("sprint_migration")
+      end
+
+      it "stores the originating version name in the cause" do
+        perform
+        expect(wp1.reload.last_journal.cause["version_name"]).to eq("Sprint A")
+        expect(wp2.reload.last_journal.cause["version_name"]).to eq("Sprint B")
+      end
+
+      it "suppresses journal notifications" do
+        allow(Journal::NotificationConfiguration).to receive(:with).and_call_original
+        perform
+        expect(Journal::NotificationConfiguration).to have_received(:with).with(false)
+      end
+    end
+
+    context "when the map contains an id that no longer exists" do
+      let(:wp_version_map) do
+        {
+          "0" => "Ghost Sprint",
+          wp1.id.to_s => "Sprint A"
+        }
+      end
+
+      it "skips the missing id and still journals the existing work package" do
+        expect { perform }.not_to raise_error
+        expect(wp1.reload.last_journal.cause["version_name"]).to eq("Sprint A")
+      end
+    end
+  end
+end
diff --git a/spec/lib/open_project/journal_formatter/cause_spec.rb b/spec/lib/open_project/journal_formatter/cause_spec.rb
index 73d42e972d5..b77d9d4b26a 100644
--- a/spec/lib/open_project/journal_formatter/cause_spec.rb
+++ b/spec/lib/open_project/journal_formatter/cause_spec.rb
@@ -550,6 +550,30 @@ RSpec.describe OpenProject::JournalFormatter::Cause do
     end
   end
 
+  context "when the change was caused by a sprint migration" do
+    subject(:cause) do
+      {
+        "type" => "system_update",
+        "feature" => "sprint_migration",
+        "version_name" => "Sprint 1"
+      }
+    end
+
+    it do
+      expect(cause).to render_html_variant(
+        "<strong>#{I18n.t('journals.caused_changes.system_update')}</strong> " \
+        "#{I18n.t('journals.cause_descriptions.system_update.sprint_migration', version_name: 'Sprint 1')}"
+      )
+    end
+
+    it do
+      expect(cause).to render_raw_variant(
+        "#{I18n.t('journals.caused_changes.system_update')} " \
+        "#{I18n.t('journals.cause_descriptions.system_update.sprint_migration', version_name: 'Sprint 1')}"
+      )
+    end
+  end
+
   context "when the change was caused by an import" do
     subject(:cause) do
       {