diff --git a/.kokoro/release.sh b/.kokoro/release.sh
index 2770d80..0505b0c 100755
--- a/.kokoro/release.sh
+++ b/.kokoro/release.sh
@@ -13,6 +13,18 @@ echo "=== Building and Releasing from: ${REPO_DIR} ==="
 # -----------------------------------------------------------------------------
 # 2. Environment & Tooling Setup
 # -----------------------------------------------------------------------------
+# Find the latest pre-installed standalone Python version in pyenv. Excludes
+# 'system' because that's a stripped Debian package without 'ensurepip', and
+# 'venv' requires 'ensurepip'.
+PYENV_VER="$(pyenv versions --bare 2>/dev/null | awk '$1 != "system" && $1 ~ /^[0-9]/' | sort -V | tail -n 1)"
+if [[ -z "${PYENV_VER}" ]]; then
+  echo "ERROR: No standalone Python version found in pyenv." >&2
+  exit 1
+fi
+
+echo "=== Activating pyenv Python version: ${PYENV_VER} ==="
+pyenv global "${PYENV_VER}"
+
 # Setup virtual environment for releasing
 python3 -m venv .venv
 source ./.venv/bin/activate