diff --git a/requirements/constraints.txt b/requirements/constraints.txt
index 0ea56b8a..a7526eb5 100644
--- a/requirements/constraints.txt
+++ b/requirements/constraints.txt
@@ -37,7 +37,7 @@ pytest-asyncio==1.3.0
 # graph. They intentionally stay constrained until a later dependency review.
 click==8.3.3
 h2==4.4.1
-idna==3.15
+idna==3.20
 pip==26.2.1
 pygments==2.20.0
 requests==2.33.0