diff --git a/dist/flexsearch.min.js b/dist/flexsearch.min.js
index 86f0c83..5044c5c 100644
--- a/dist/flexsearch.min.js
+++ b/dist/flexsearch.min.js
@@ -5,27 +5,26 @@
  * Licence: Apache-2.0
  * https://github.com/nextapps-de/flexsearch
  */
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diff --git a/package.json b/package.json
index 6aa9baf..f69ff1f 100644
--- a/package.json
+++ b/package.json
@@ -17,7 +17,7 @@
     "url": "https://github.com/nextapps-de/flexsearch/issues",
     "email": "info@nextapps.de"
   },
-  "main": "dist/flexsearch.node.js",
+  "main": "dist/flexsearch.min.js",
   "browser": "dist/flexsearch.min.js",
   "types": "index.d.ts",
   "preferGlobal": false,
diff --git a/src/adapter.js b/src/adapter.js
index 80ed250..70a844e 100644
--- a/src/adapter.js
+++ b/src/adapter.js
@@ -17,7 +17,7 @@ function WorkerAdapter(id, options){
         id = 0;
     }
 
-    if(is_function(options["encode"])){
+    if(options && is_function(options["encode"])){
 
         options["encode"] = options["encode"].toString();
     }
diff --git a/src/document.js b/src/document.js
index 179ca82..a6d4e52 100644
--- a/src/document.js
+++ b/src/document.js
@@ -452,7 +452,7 @@ Document.prototype.remove = function(id){
     return this;
 };
 
-Document.prototype.search = async function(query, limit, options){
+Document.prototype.search = function(query, limit, options, resolve){
 
     if(is_object(query)){
 
@@ -536,11 +536,11 @@ Document.prototype.search = async function(query, limit, options){
     field || (field = this.field);
     bool = bool && ((field.length > 1) || (tag && (tag.length > 1)));
 
-    let async_res = [];
-
     // use Promise.all to get a change of processing requests in parallel
 
-    if(this.worker || this.async){
+    if(!resolve && (this.worker || this.async)){
+
+        resolve = [];
 
         for(let i = 0, key; i < field.length; i++){
 
@@ -558,10 +558,17 @@ Document.prototype.search = async function(query, limit, options){
                 opt = field_options[key];
             }
 
-            async_res[i] = this.index[key].searchAsync(query, limit, opt || options);
+            resolve[i] = this.index[key].searchAsync(query, limit, opt || options);
         }
 
-        async_res = await Promise.all(async_res);
+        const self = this;
+
+        // anyone knows a better workaround of optionally having async promises?
+
+        return Promise.all(resolve).then(function(resolve){
+
+            self.search(query, limit, options, resolve);
+        });
     }
 
     // TODO solve this in one loop below
@@ -582,9 +589,9 @@ Document.prototype.search = async function(query, limit, options){
             opt = field_options[key];
         }
 
-        if(this.worker || this.async){
+        if(resolve){
 
-            res = async_res[i];
+            res = resolve[i];
         }
         else{
 
diff --git a/src/type.js b/src/type.js
index 10772bd..0ca900e 100644
--- a/src/type.js
+++ b/src/type.js
@@ -50,5 +50,7 @@ IndexInterface.prototype.remove;
 export function DocumentInterface(){
 
     this.field = null;
+
+    /** @type IndexInterface */
     this.index = null;
 }
diff --git a/src/webpack.js b/src/webpack.js
index 3724eab..b4888aa 100644
--- a/src/webpack.js
+++ b/src/webpack.js
@@ -1,6 +1,7 @@
 import { SUPPORT_ASYNC, SUPPORT_DOCUMENT, SUPPORT_CACHE, SUPPORT_SERIALIZE } from "./config.js";
 import Document from "./document.js";
 import Index from "./index.js";
+import WorkerAdapter from "./adapter.js";
 import { registerCharset, registerLanguage } from "./global.js";
 
 /** @export */ Document.prototype.add;
@@ -44,15 +45,35 @@ if(SUPPORT_SERIALIZE){
 
 /** @export */ Index.prototype.export;
 /** @export */ Index.prototype.import;
-
 /** @export */ Document.prototype.export;
 /** @export */ Document.prototype.import;
 }
 
-window["FlexSearch"] = {
+const root = self || window;
+
+const FlexSearch = {
 
     "Index": Index,
     "Document": SUPPORT_DOCUMENT ? Document : null,
+    "WorkerAdapter": WorkerAdapter,
     "registerCharset": registerCharset,
     "registerLanguage": registerLanguage
-};
\ No newline at end of file
+};
+
+let tmp;
+
+if((tmp = root["define"]) && tmp["amd"]){
+
+    tmp([], function(){
+
+        return FlexSearch;
+    });
+}
+else if(root["exports"]){
+
+    root["exports"] = FlexSearch;
+}
+else{
+
+    root["FlexSearch"] = FlexSearch;
+}
diff --git a/task/build.js b/task/build.js
index 448aaa6..f484f9e 100644
--- a/task/build.js
+++ b/task/build.js
@@ -136,8 +136,8 @@ let parameter = (function(opt){
     dependency_mode: "PRUNE_LEGACY",
     rewrite_polyfills: use_polyfill || false,
 
-    isolation_mode: "IIFE"
-    //output_wrapper: "(function(){%output%}());"
+    // isolation_mode: "IIFE",
+    output_wrapper: "(function(self){%output%}(module));"
 
     //formatting: "PRETTY_PRINT"
 });