diff --git a/application/source/util/processing.mjs b/application/source/util/processing.mjs
index 95c0f5932900989e18a3403f75173650ee67bb03..2f9ece33ba7006c63443c70dd928e9fe1ba1bfe2 100644
--- a/application/source/util/processing.mjs
+++ b/application/source/util/processing.mjs
@@ -5,14 +5,14 @@
  * License text available at https://www.gnu.org/licenses/agpl-3.0.en.html
  */
 
-import { internalSymbol } from "../constants.mjs";
-import { Base } from "../types/base.mjs";
-import { getGlobalFunction } from "../types/global.mjs";
-import { isFunction, isInteger } from "../types/is.mjs";
-import { Queue } from "../types/queue.mjs";
-import { validateFunction, validateInteger } from "../types/validate.mjs";
+import {internalSymbol} from "../constants.mjs";
+import {Base} from "../types/base.mjs";
+import {getGlobalFunction} from "../types/global.mjs";
+import {isFunction, isInteger} from "../types/is.mjs";
+import {Queue} from "../types/queue.mjs";
+import {validateFunction, validateInteger} from "../types/validate.mjs";
 
-export { Processing };
+export {Processing};
 
 /**
  * @private
@@ -86,9 +86,8 @@ class Processing extends Base {
      *
      * So the execution time is timeout1+timeout1+timeout1+timeout2
      *
-     * @param {int} timeout Timeout
-     * @param {function} callback Callback
      * @throw {TypeError} the arguments must be either integer or functions
+     * @param {...(int|function)} args
      */
     constructor(...args) {
         super();
@@ -136,13 +135,17 @@ class Processing extends Base {
      */
     run(data) {
         const self = this;
-        if (this[internalSymbol].queue.isEmpty()) {
+        if (self[internalSymbol].queue.isEmpty()) {
             return Promise.resolve(data);
         }
 
-        return this[internalSymbol].queue
-            .poll()
-            .run(data)
+        const callback = self[internalSymbol].queue.poll();
+
+        if (callback === null || callback === undefined) {
+            return Promise.resolve(data);
+        }
+
+        return callback.run(data)
             .then((result) => {
                 return self.run(result);
             });