diff --git a/build b/build
index 415a2faa686e..47a058fd30d9 100755
--- a/build
+++ b/build
@@ -30,11 +30,6 @@ try {
 	console.log('Installing dependencies...');
 	shell('npm install');
 }
-// for some reason, esbuild won't be requirable until a tick has passed
-// see https://stackoverflow.com/questions/53270058/node-cant-find-certain-modules-after-synchronous-install
-setImmediate(() => {
-	require('./tools/build-utils').transpile(force, decl);
-});
 
 // Make sure config.js exists. If not, copy it over synchronously from
 // config-example.js, since it's needed before we can start the server
@@ -49,3 +44,11 @@ try {
 		fs.readFileSync('config/config-example.js')
 	);
 }
+
+// for some reason, esbuild won't be requirable until a tick has passed
+// see https://stackoverflow.com/questions/53270058/node-cant-find-certain-modules-after-synchronous-install
+setImmediate(() => {
+	// npm package, don't rebuild
+	if (process.argv[2] === 'postinstall' && fs.existsSync('dist')) return;
+	require('./tools/build-utils').transpile(force, decl);
+});
diff --git a/package.json b/package.json
index 31c63cb5f088..cdec72108bd5 100644
--- a/package.json
+++ b/package.json
@@ -40,7 +40,7 @@
     "test": "mocha",
     "posttest": "npm run tsc",
     "full-test": "npm run lint && npm run tsc && mocha --timeout 8000 --forbid-only -g \".*\"",
-    "postinstall": "npm run build"
+    "postinstall": "npm run build postinstall"
   },
   "bin": "./pokemon-showdown",
   "homepage": "http://pokemonshowdown.com",