Company: OSBC
Filing Date: 2025-05-06
Form Type: S-4/A
Source: 0001104659-25-045103
Chunk: 394

Company: OLD SECOND BANCORP INC
Filing Date: 2025-05-06
Form: S-4/A
Chunk 394
---
 THIS AGREEMENT EARLIER). THE EXECUTIVE AND THE COMPANY, BY ITS DESIGNATED REPRESENTATIVE, HEREBY ACKNOWLEDGE THAT THEY HAVE READ AND UNDERSTAND EACH OF THE PROVISIONS OF THIS AGREEMENT, THAT THEY HAVE EXECUTED THIS AGREEMENT VOLUNTARILY AND WITH FULL KNOWLEDGE OF ITS SIGNIFICANCE, AND THAT THEY INTEND TO BE FULLY BOUND BY THE SAME.

| ​ | OLD SECOND BANCORP, INC. |   |   |                                  | ​ | ​ | DARIN CAMPBELL |   |   |   | ​ |
| ​ | By:                      | ​ | ​ | ​                                | ​ | ​ | By:            | ​ | ​ | ​ | ​ |
| ​ | ​                        | ​ | ​ | Chris Lasse, SVP Human Resources | ​ | ​ | ​              | ​ | ​ | ​ | ​ |
| ​ | Date:                    | ​ | ​ | ​                                | ​ | ​ | Date:          | ​ | ​ | ​ | ​ |

C-1-12

TABLE OF CONTENTS

### EXHIBIT A
<div align='center'>[ Omitted pursuant to Item 601(b)(2) of Regulation S-K ]

C-1-13</div>

TABLE OF CONTENTS

### COMPENSATION AND BENEFITS

### ASSURANCE AGREEMENT

#### Darin Campbell

### EXECUTIVE
<div align='center'>C-1-14</div>

TABLE OF CONTENTS

### COMPENSATION AND BENEFITS ASSURANCE AGREEMENT
This COMPENSATION AND BENEFITS ASSURANCE AGREEMENT (this “

#### Agreement
”) is made, entered into, and is effective as of [ , 2025] (the “

#### Effective Date
”) by and between OLD SECOND BANCORP, INC. (hereinafter referred to as the “

#### Company
”) and DARIN CAMPBELL (hereinafter referred to as the “

#### Executive
”).

WHEREAS, the Executive will be employed by the Company in a key management capacity; and

WHEREAS, the Company recognizes that circumstances may arise in which a Change in Control may occur, thereby causing uncertainty of employment without regard to the competence or past contributions of the Executive, which uncertainty may result in the loss of valuable services of the Executive, and the parties wish to provide reasonable security to the Executive against changes in the employment relationship