diff --git a/installation/constraints-3.9.txt b/installation/constraints-3.9.txt
index 92a185c..ad74026 100644
--- a/installation/constraints-3.9.txt
+++ b/installation/constraints-3.9.txt
@@ -26,6 +26,6 @@ requests==2.32.5
 rocrate==0.15.1
 scipy==1.13.1
 six==1.17.0
-tzdata==2026.3
+tzdata==2026.4
 urllib3==2.6.3
 zipp==3.23.1