diff --git a/windmill-worker/src/python_versions.rs b/windmill-worker/src/python_versions.rs
index 3d71e9f9ec..c9166b52c6 100644
--- a/windmill-worker/src/python_versions.rs
+++ b/windmill-worker/src/python_versions.rs
@@ -326,6 +326,7 @@ impl PyV {
     }
 
     pub async fn list_available_python_versions() -> Vec<Self> {
+        return vec![PyVAlias::Py312.into()];
         match Self::list_available_python_versions_inner().await {
             Ok(pyvs) => pyvs,
             Err(e) => {
@@ -591,6 +592,10 @@ impl PyV {
         w_id: &str,
         occupancy_metrics: &mut Option<&mut OccupancyMetrics>,
     ) -> error::Result<()> {
+        let v = self.to_string();
+        append_logs(job_id, w_id, format!("\nREQUESTED PYTHON INSTALL IGNORED ({})", v), conn).await;
+        return Err(error::Error::BadConfig(format!("Python is managed through the NixOS system configuration. Change the Windmill instance setting to version '3.12'")));
+
         let v = self.to_string();
         append_logs(job_id, w_id, format!("\nINSTALLING PYTHON ({})", v), conn).await;
         // Create dirs for newly installed python
@@ -695,11 +700,11 @@ impl PyV {
                 "find",
                 &self.to_string(),
                 "--system",
-                "--python-preference=only-managed",
+                "--python-preference=only-system",
             ])
             .envs([
                 ("UV_PYTHON_INSTALL_DIR", PY_INSTALL_DIR),
-                ("UV_PYTHON_PREFERENCE", "only-managed"),
+                ("UV_PYTHON_PREFERENCE", "only-system"),
             ])
             // .stdout(Stdio::piped())
             .stderr(Stdio::piped())