diff --git a/src/index.js b/src/index.js
index 1596f2c7..bdf73f88 100644
--- a/src/index.js
+++ b/src/index.js
@@ -18,18 +18,10 @@ function lessLoader(source) {
     baseDataPath: 'options',
   });
 
-  const done = this.async();
-  const isSync = typeof done !== 'function';
-
-  if (isSync) {
-    throw new Error(
-      'Synchronous compilation is not supported anymore. See https://github.com/webpack-contrib/less-loader/issues/84'
-    );
-  }
-
+  const callback = this.async();
   const lessOptions = getLessOptions(this, options);
 
-  processResult(this, render(source, lessOptions));
+  processResult(this, render(source, lessOptions), callback);
 }
 
 export default lessLoader;
diff --git a/src/processResult.js b/src/processResult.js
index 1b9bdd16..fff9074d 100644
--- a/src/processResult.js
+++ b/src/processResult.js
@@ -6,10 +6,9 @@ const formatLessError = require('./formatLessError');
  *
  * @param {loaderContext} loaderContext
  * @param {Promise<LessResult>} resultPromise
+ * @param {Function} callback
  */
-function processResult(loaderContext, resultPromise) {
-  const { callback } = loaderContext;
-
+function processResult(loaderContext, resultPromise, callback) {
   resultPromise
     .then(
       ({ css, map, imports }) => {