diff --git a/sections/errorhandling/operationalvsprogrammererror.russian.md b/sections/errorhandling/operationalvsprogrammererror.russian.md
index b4942cb1..544dbd3c 100644
--- a/sections/errorhandling/operationalvsprogrammererror.russian.md
+++ b/sections/errorhandling/operationalvsprogrammererror.russian.md
@@ -6,9 +6,12 @@
 
 ### Пример кода - пометка ошибки как рабочей (доверенной)
 
+<details>
+<summary><strong>Javascript</strong></summary>
+
 ```javascript
 // marking an error object as operational 
-const myError = new Error("How can I add new product when no value provided?");
+const myError = new Error('How can I add new product when no value provided?');
 myError.isOperational = true;
 
 // or if you're using some centralized error factory (see other examples at the bullet "Use only the built-in Error object")
@@ -22,9 +25,37 @@ class AppError {
   }
 };
 
-throw new AppError(errorManagement.commonErrors.InvalidInput, "Describe here what happened", true);
+throw new AppError(errorManagement.commonErrors.InvalidInput, 'Describe here what happened', true);
 
 ```
+</details>
+
+<details>
+<summary><strong>Typescript</strong></summary>
+
+```typescript
+// some centralized error factory (see other examples at the bullet "Use only the built-in Error object")
+export class AppError extends Error {
+  public readonly commonType: string;
+  public readonly isOperational: boolean;
+
+  constructor(commonType: string, description: string, isOperational: boolean) {
+    super(description);
+
+    Object.setPrototypeOf(this, new.target.prototype); // restore prototype chain
+
+    this.commonType = commonType;
+    this.isOperational = isOperational;
+
+    Error.captureStackTrace(this);
+  }
+}
+
+// marking an error object as operational (true)
+throw new AppError(errorManagement.commonErrors.InvalidInput, 'Describe here what happened', true);
+
+```
+</details>
 
 ### Цитата блога: "Ошибки программиста - это ошибки в программе"