diff --git a/default.nix b/default.nix
index 47d94f37..d82be7f9 100644
--- a/default.nix
+++ b/default.nix
@@ -22,6 +22,10 @@ let
     cargo = rustToolchain;
   };
 
+  himalayaExe =
+    let ext = lib.optionalString hostPlatform.isWindows ".exe";
+    in "${hostPlatform.emulator pkgs.buildPackages} ./himalaya${ext}";
+
   himalaya = import ./package.nix {
     inherit lib hostPlatform rustPlatform;
     fetchFromGitHub = pkgs.fetchFromGitHub;
@@ -33,6 +37,7 @@ let
     notmuch = pkgs.notmuch;
     gpgme = pkgs.gpgme;
   };
+
 in
 
 himalaya.overrideAttrs (drv: {
@@ -46,12 +51,12 @@ himalaya.overrideAttrs (drv: {
     cp assets/himalaya-watch@.service $out/bin/share/services/
 
     cd $out/bin
-    ${hostPlatform.emulator pkgs.buildPackages} ./himalaya man ./share/man
-    ${hostPlatform.emulator pkgs.buildPackages} ./himalaya completion bash > ./share/completions/himalaya.bash
-    ${hostPlatform.emulator pkgs.buildPackages} ./himalaya completion elvish > ./share/completions/himalaya.elvish
-    ${hostPlatform.emulator pkgs.buildPackages} ./himalaya completion fish > ./share/completions/himalaya.fish
-    ${hostPlatform.emulator pkgs.buildPackages} ./himalaya completion powershell > ./share/completions/himalaya.powershell
-    ${hostPlatform.emulator pkgs.buildPackages} ./himalaya completion zsh > ./share/completions/himalaya.zsh
+    ${himalayaExe} man ./share/man
+    ${himalayaExe} completion bash > ./share/completions/himalaya.bash
+    ${himalayaExe} completion elvish > ./share/completions/himalaya.elvish
+    ${himalayaExe} completion fish > ./share/completions/himalaya.fish
+    ${himalayaExe} completion powershell > ./share/completions/himalaya.powershell
+    ${himalayaExe} completion zsh > ./share/completions/himalaya.zsh
 
     ${lib.getExe pkgs.buildPackages.gnutar} -czf himalaya.tgz himalaya* share
     mv himalaya.tgz ../