diff --git a/requirements.txt b/requirements.txt
index b5f06fe..ea68a8c 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -4,7 +4,7 @@ certifi==2024.8.30
     # via requests
 charset-normalizer==3.4.0
     # via requests
-idna==3.10
+idna==3.15
     # via requests
 importlib-resources==6.4.5
     # via dials-data (pyproject.toml)
diff --git a/requirements_dev.txt b/requirements_dev.txt
index ff4db0a..140dd4f 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -6,7 +6,7 @@ charset-normalizer==3.4.0
     # via requests
 coverage==7.3.1
     # via dials-data (pyproject.toml)
-idna==3.10
+idna==3.15
     # via requests
 importlib-resources==6.4.5
     # via dials-data (pyproject.toml)
diff --git a/requirements_doc.txt b/requirements_doc.txt
index 6908463..fecbdc1 100644
--- a/requirements_doc.txt
+++ b/requirements_doc.txt
@@ -12,7 +12,7 @@ docutils==0.18.1
     # via
     #   sphinx
     #   sphinx-rtd-theme
-idna==3.10
+idna==3.15
     # via requests
 imagesize==1.4.1
     # via sphinx