diff --git a/pkgs/by-name/em/emmet-language-server/package.nix b/pkgs/by-name/em/emmet-language-server/package.nix
index cb4eb5393f93..a8cc88056844 100644
--- a/pkgs/by-name/em/emmet-language-server/package.nix
+++ b/pkgs/by-name/em/emmet-language-server/package.nix
@@ -8,6 +8,8 @@
   pnpmBuildHook,
   fetchFromGitHub,
   nix-update-script,
+  runCommand,
+  emmet-language-server,
 }:
 let
   pnpm = pnpm_11;
@@ -60,7 +62,24 @@ stdenvNoCC.mkDerivation (finalAttrs: {
     runHook postInstall
   '';
 
-  passthru.updateScript = nix-update-script { };
+  passthru = {
+    updateScript = nix-update-script { };
+
+    tests.smoke = runCommand "emmet-language-server-smoke-test" { } ''
+      INIT_REQUEST='{"jsonrpc":"2.0","id":1,"method":"initialize","params":{"processId":null,"rootUri":"file:///tmp","workspaceFolders":[{"uri":"file:///tmp","name":"test"}],"capabilities":{}}}'
+      CONTENT_LENGTH=''${#INIT_REQUEST}
+
+      RESPONSE=$(
+        {
+          printf "Content-Length: %d\r\n\r\n%s" "$CONTENT_LENGTH" "$INIT_REQUEST"
+          sleep 1
+        } | timeout 3  ${lib.getExe emmet-language-server} --stdio 2>&1 | head -c 1000
+      ) || true
+
+      echo "$RESPONSE" | grep -q '"capabilities"'
+      touch $out
+    '';
+  };
 
   meta = {
     description = "Language server for emmet.io";