diff --git a/docker-compose.yaml b/docker-compose.yaml
index 2aab620..d1ca47c 100755
--- a/docker-compose.yaml
+++ b/docker-compose.yaml
@@ -8,6 +8,7 @@ services:
     environment:
       - HTTPS_PORT=2093
       # host.docker.internal zeigt auf den Docker-Host → erreicht andere Stacks per Port
+      - PYTHON_BIN=python3
       - WEBCAM_URL=http://host.docker.internal:8444
       - BODYTRACKER_URL=http://host.docker.internal:8446
     extra_hosts:
diff --git a/server/server.js b/server/server.js
index 87fe677..c260dac 100755
--- a/server/server.js
+++ b/server/server.js
@@ -342,7 +342,7 @@ app.post('/api/calibration/foto', async (req, res) => {
  * Abschluss:
  *   data: {"type":"done","exitCode":0}
  */
-const PYTHON_BIN     = process.env.PYTHON_BIN     || 'python';
+const PYTHON_BIN     = process.env.PYTHON_BIN     || 'python3';
 const calibScriptPath = path.join(__dirname, '..', 'scripts', 'callibriate.py');
 
 app.post('/api/calibration/compute', async (req, res) => {