diff --git a/flake.nix b/flake.nix
index 50af1b7..defc7f4 100644
--- a/flake.nix
+++ b/flake.nix
@@ -77,6 +77,11 @@ rust-project TODO: write shell script for automatically updating `cargoHash`
           meta = meta // {
             description = "Using nextcloud notes to track time usage.";
           };
+
+          postFixup = ''
+            wrapProgram $out/bin/time_tracker \
+              --prefix PATH : "${lib.makeBinPath [ msmtp ]}"
+          '';
         });
       };
       nixosModules.default = { config, ... }: let