diff --git a/pkgs/development/libraries/fmt/default.nix b/pkgs/development/libraries/fmt/default.nix
index b789956dfe56..f0cc0dd8dc25 100644
--- a/pkgs/development/libraries/fmt/default.nix
+++ b/pkgs/development/libraries/fmt/default.nix
@@ -90,4 +90,9 @@ in
     version = "11.2.0";
     hash = "sha256-sAlU5L/olxQUYcv8euVYWTTB8TrVeQgXLHtXy8IMEnU=";
   };
+
+  fmt_12 = generic {
+    version = "12.0.0";
+    hash = "sha256-AZDmIeU1HbadC+K0TIAGogvVnxt0oE9U6ocpawIgl6g=";
+  };
 }
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index bd669e9b308c..3e728ac43394 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -7473,7 +7473,12 @@ with pkgs;
   fltk = fltk13;
   fltk-minimal = fltk13-minimal;
 
-  inherit (callPackages ../development/libraries/fmt { }) fmt_9 fmt_10 fmt_11;
+  inherit (callPackages ../development/libraries/fmt { })
+    fmt_9
+    fmt_10
+    fmt_11
+    fmt_12
+    ;
 
   fmt = fmt_10;