diff --git a/docs/conf.py b/docs/conf.py
index 4fe6a3d..da51d3d 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -6,7 +6,7 @@ import amaranth
 project = "Amaranth HDL toolchain"
 version = amaranth.__version__
 release = version.split("+")[0]
-copyright = "2020—2021, Amaranth HDL developers"
+copyright = "2020—2023, Amaranth HDL developers"
 
 extensions = [
 	"sphinx.ext.intersphinx",
diff --git a/docs/requirements.txt b/docs/requirements.txt
index 3232632..88045bd 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -1,3 +1,3 @@
-sphinx~=4.2
+sphinx~=6.1
 sphinxcontrib-platformpicker~=1.3
-sphinx-rtd-theme~=1.0
+sphinx-rtd-theme~=1.2