diff --git a/ci/create_venv.sh b/ci/create_venv.sh
index fec187e..147085a 100755
--- a/ci/create_venv.sh
+++ b/ci/create_venv.sh
@@ -3,6 +3,13 @@
 python3 -m venv venv
 source venv/bin/activate
 python3 -c 'import sys; print("Python version:", sys.version)'
+
+# Until amaranth 0.4 is published, Pythons newer than 3.9 need to install from git.
+if [ "$(python3 -c 'import sys; print(sys.version_info[1])')" -gt 9 ]; then
+	echo "Using Amaranth from GitHub as Python >3.9 (remove after Amaranth 0.4 is released)."
+	pip3 install "git+https://github.com/amaranth-lang/amaranth.git#egg=amaranth"
+fi
+
 pip3 install .
 pip3 install unittest-parallel
 pip3 install flake8