diff --git a/nixos/doc/manual/release-notes/rl-2505.section.md b/nixos/doc/manual/release-notes/rl-2505.section.md
index d55b5bfd42a7..10645d55e838 100644
--- a/nixos/doc/manual/release-notes/rl-2505.section.md
+++ b/nixos/doc/manual/release-notes/rl-2505.section.md
@@ -4,7 +4,7 @@
 
 <!-- To avoid merge conflicts, consider adding your item at an arbitrary place in the list instead. -->
 
-- Create the first release note entry in this section!
+- The default PHP version has been updated to 8.3.
 
 <!-- To avoid merge conflicts, consider adding your item at an arbitrary place in the list instead. -->
 
diff --git a/nixos/modules/services/web-apps/castopod.nix b/nixos/modules/services/web-apps/castopod.nix
index d3750c3dd393..e60a9b3b1fb7 100644
--- a/nixos/modules/services/web-apps/castopod.nix
+++ b/nixos/modules/services/web-apps/castopod.nix
@@ -6,7 +6,7 @@ let
   user = "castopod";
 
   # https://docs.castopod.org/getting-started/install.html#requirements
-  phpPackage = pkgs.php.withExtensions ({ enabled, all }: with all; [
+  phpPackage = pkgs.php82.withExtensions ({ enabled, all }: with all; [
     intl
     curl
     mbstring
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 03c9fcccf3b6..98a076259d50 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -7438,7 +7438,7 @@ with pkgs;
   # PHP interpreters, packages and extensions.
   #
   # Set default PHP interpreter, extensions and packages
-  php = php82;
+  php = php83;
   phpExtensions = php.extensions;
   phpPackages = php.packages;