diff --git a/requirements/dev.txt b/requirements/dev.txt
index a5ed17e..8da3eac 100644
--- a/requirements/dev.txt
+++ b/requirements/dev.txt
@@ -72,7 +72,7 @@ packaging==24.1
     #   pytest
     #   sphinx
     #   tox
-pallets-sphinx-themes==2.1.3
+pallets-sphinx-themes==2.3.0
     # via -r docs.in
 pip-tools==7.4.1
     # via -r dev.in
@@ -122,10 +122,13 @@ sphinx==8.0.2
     #   -r docs.in
     #   pallets-sphinx-themes
     #   sphinx-issues
+    #   sphinx-notfound-page
     #   sphinx-tabs
     #   sphinxcontrib-log-cabinet
 sphinx-issues==4.1.0
     # via -r docs.in
+sphinx-notfound-page==1.1.0
+    # via pallets-sphinx-themes
 sphinx-tabs==3.4.5
     # via -r docs.in
 sphinxcontrib-applehelp==1.0.8
diff --git a/requirements/docs.txt b/requirements/docs.txt
index 05f13ed..a359668 100644
--- a/requirements/docs.txt
+++ b/requirements/docs.txt
@@ -28,7 +28,7 @@ packaging==24.0
     # via
     #   pallets-sphinx-themes
     #   sphinx
-pallets-sphinx-themes==2.1.3
+pallets-sphinx-themes==2.3.0
     # via -r docs.in
 pygments==2.18.0
     # via
@@ -43,10 +43,13 @@ sphinx==8.0.2
     #   -r docs.in
     #   pallets-sphinx-themes
     #   sphinx-issues
+    #   sphinx-notfound-page
     #   sphinx-tabs
     #   sphinxcontrib-log-cabinet
 sphinx-issues==4.1.0
     # via -r docs.in
+sphinx-notfound-page==1.1.0
+    # via pallets-sphinx-themes
 sphinx-tabs==3.4.5
     # via -r docs.in
 sphinxcontrib-applehelp==1.0.8