---
schema_version: "secwatch.filing_event.v1"
accession: "0000357173-26-000028"
form_type: "8-K"
ticker: "OSBC"
cik: "0000357173"
company_name: "OLD SECOND BANCORP INC"
filed_at: "2026-06-09T15:00:08+00:00"
generated_at: "2026-06-09T15:01:21.566289+00:00"
event_type: "leadership"
sentiment: "neutral"
materiality_score: 0.35
calibrated_materiality_score: 0.35
confidence: "high"
source: SEC EDGAR
---

# Director Dennis Klaeser resigns from Old Second Bancorp board, effective June 5, 2026

## Summary
- Dennis Klaeser resigned from the Board and Old Second National Bank board, effective immediately.
- Resignation not due to any disagreement with the company; served since 2021.
- Klaeser served on Executive, Audit, Compensation, Risk, and Capital Committees.
- Board size reduced by one; vacancy not immediately filled.
- Mr. Klaeser was a Class II director with term expiring at 2027 annual meeting.

## SEC filing metadata
- accession: 0000357173-26-000028
- form_type: 8-K
- ticker: OSBC
- cik: 0000357173
- company_name: OLD SECOND BANCORP INC
- filed_at: 2026-06-09T15:00:08+00:00
- event_type: leadership
- sentiment: neutral
- materiality_score: 0.35
- calibrated_materiality_score: 0.35
- confidence: high
- sec_items: 5.02
- EDGAR index: https://www.sec.gov/Archives/edgar/data/357173/000035717326000028/0000357173-26-000028-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/357173/000035717326000028/osbc-20260605x8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0000357173-26-000028
- JSON: https://secwatch.observer/filing/0000357173-26-000028.json
- Plain text: https://secwatch.observer/filing/0000357173-26-000028.txt

## Key facts
- Executive change
  Dennis Klaeser resigned as Director at OLD SECOND BANCORP INC.
  - Action: resigned
  - Role: Director
  source text: On June 5, 2026, Dennis Klaeser, a member of the Board of Directors (the “Board”) of Old Second Bancorp, Inc. (“Old Second”) and the Board of Directors (the “Bank Board”) of its subsidiary bank, Old Second National Bank, notified Old Second of his resignation from the Board and Bank Board.
  evidence_url: https://www.sec.gov/Archives/edgar/data/357173/000035717326000028/0000357173-26-000028-index.htm

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.