diff --git a/nixos/doc/manual/release-notes/rl-2405.section.md b/nixos/doc/manual/release-notes/rl-2405.section.md
index aba4d3d72d1d..561ddbb8d99e 100644
--- a/nixos/doc/manual/release-notes/rl-2405.section.md
+++ b/nixos/doc/manual/release-notes/rl-2405.section.md
@@ -67,8 +67,9 @@ The pre-existing [services.ankisyncd](#opt-services.ankisyncd.enable) has been m
 
 - The legacy and long deprecated systemd target `network-interfaces.target` has been removed. Use `network.target` instead.
 
-- `mkosi` was updated to v19. Parts of the user interface have changed. Consult the
-  [release notes](https://github.com/systemd/mkosi/releases/tag/v19) for a list of changes.
+- `mkosi` was updated to v20. Parts of the user interface have changed. Consult the
+  release notes of [v19](https://github.com/systemd/mkosi/releases/tag/v19) and
+  [v20](https://github.com/systemd/mkosi/releases/tag/v20) for a list of changes.
 
 - `services.nginx` will no longer advertise HTTP/3 availability automatically. This must now be manually added, preferably to each location block.
   Example:
diff --git a/pkgs/tools/virtualization/mkosi/default.nix b/pkgs/tools/virtualization/mkosi/default.nix
index bb823b516977..e792b25bf41e 100644
--- a/pkgs/tools/virtualization/mkosi/default.nix
+++ b/pkgs/tools/virtualization/mkosi/default.nix
@@ -10,6 +10,9 @@
 , gnutar
 , util-linux
 , cpio
+, bash
+, coreutils
+, btrfs-progs
 
   # Python packages
 , setuptools
@@ -55,7 +58,7 @@ let
 in
 buildPythonApplication rec {
   pname = "mkosi";
-  version = "19";
+  version = "20";
   format = "pyproject";
 
   outputs = [ "out" "man" ];
@@ -64,7 +67,7 @@ buildPythonApplication rec {
     owner = "systemd";
     repo = "mkosi";
     rev = "v${version}";
-    hash = "sha256-KjJM+KZCgUnsaEN2ZorhH0AR5nmiV2h3i7Vb3KdGFtI=";
+    hash = "sha256-MXpjgU+Vt9EMCeZ55OcgMnkvuN+ln2EvbNxKbonzueU=";
   };
 
   # Fix ctypes finding library
@@ -88,7 +91,10 @@ buildPythonApplication rec {
   ];
 
   propagatedBuildInputs = [
+    bash
+    btrfs-progs
     bubblewrap
+    coreutils
     cpio
     gnutar
     kmod