diff --git a/requirements/dev.txt b/requirements/dev.txt
index d0b31fc..1619cd3 100644
--- a/requirements/dev.txt
+++ b/requirements/dev.txt
@@ -14,7 +14,7 @@ mypy>=1.20.2,<2.0.0
 pyright>=1.1.409
 
 # Type stubs (compatible versions)
-types-python-dateutil>=2.8.0.0
+types-python-dateutil>=2.9.0.20260508
 types-openpyxl>=3.1.0.0
 types-tabulate>=0.10.0.20260408
 # Note: python-dotenv has inline types (py.typed), no stub package needed