diff --git a/runtime/src/runtime/process.py b/runtime/src/runtime/process.py
index e073bd7..cbe9600 100644
--- a/runtime/src/runtime/process.py
+++ b/runtime/src/runtime/process.py
@@ -69,7 +69,7 @@ JUPYTER_MAX_LIFETIME_SECONDS = int(
 # which also registers the Python 3.8 / 3.10 kernelspecs under that venv's
 # share/jupyter/kernels tree. The runtime only launches the server here;
 # user code runs in the per-kernel venv the user picks in the Notebook UI.
-JUPYTER_VENV = os.environ.get("JUPYTER_VENV", "/opt/venv/python3.8")
+JUPYTER_VENV = os.environ.get("JUPYTER_VENV", "/opt/venv/python3.12")
 JUPYTER_BIN = os.path.join(JUPYTER_VENV, "bin", "jupyter")
 
 # Sidecar metadata file written next to the workspace directory. Holds