diff --git a/changelog.md b/changelog.md
index 933a260c..5b7d9245 100644
--- a/changelog.md
+++ b/changelog.md
@@ -1,6 +1,6 @@
 # ChangeLog
 
-## [8.1.3 (unreleased)](https://github.com/kdeldycke/mail-deduplicate/compare/v8.1.2...main)
+## [9.0.0 (unreleased)](https://github.com/kdeldycke/mail-deduplicate/compare/v8.1.2...main)
 
 > [!IMPORTANT]
 > This version is not released yet and is under active development.
diff --git a/citation.cff b/citation.cff
index 1fdb6918..2e412da8 100644
--- a/citation.cff
+++ b/citation.cff
@@ -8,8 +8,8 @@ authors:
     email: kevin@deldycke.com
     orcid: "https://orcid.org/0000-0001-9748-9014"
 doi: 10.5281/zenodo.7364256
-version: 8.1.3
+version: 9.0.0
 # The release date is kept up to date by the external workflows. See:
 # https://github.com/kdeldycke/workflows/blob/33b704b489c1aa18b7b7efbf963e153e91e1c810/.github/workflows/changelog.yaml#L135-L137
-date-released: 2025-12-02
+date-released: 2025-12-09
 url: "https://github.com/kdeldycke/mail-deduplicate"
diff --git a/mail_deduplicate/__init__.py b/mail_deduplicate/__init__.py
index 215b0227..534f85a5 100644
--- a/mail_deduplicate/__init__.py
+++ b/mail_deduplicate/__init__.py
@@ -17,4 +17,4 @@
 
 from __future__ import annotations
 
-__version__ = "8.1.3"
+__version__ = "9.0.0"
diff --git a/pyproject.toml b/pyproject.toml
index 462422c1..c67625b3 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,7 +1,7 @@
 [project]
 # Docs: https://packaging.python.org/en/latest/guides/writing-pyproject-toml/
 name = "mail-deduplicate"
-version = "8.1.3"
+version = "9.0.0"
 # Python versions and their status: https://devguide.python.org/versions/
 requires-python = ">= 3.10"
 description = "📧 CLI to deduplicate mails from mail boxes"
@@ -109,8 +109,8 @@ mdedup = "mail_deduplicate.__main__:main"
 product-name = "Mail Deduplicate"
 file-description = "📧 CLI to deduplicate mails from mail boxes"
 copyright = "Kevin Deldycke <kevin@deldycke.com> and contributors. Distributed under GPL-2.0-or-later license."
-file-version = "8.1.3"
-product-version = "8.1.3"
+file-version = "9.0.0"
+product-version = "9.0.0"
 macos-app-icon = "docs/assets/icon.png"
 linux-icon = "docs/assets/icon.png"
 windows-icon-from-ico = "docs/assets/icon.png"
@@ -140,7 +140,7 @@ addopts = [
 xfail_strict = true
 
 [tool.bumpversion]
-current_version = "8.1.3"
+current_version = "9.0.0"
 allow_dirty = true
 
 [[tool.bumpversion.files]]