diff --git a/deployments/main/docker-compose.yaml b/deployments/main/docker-compose.yaml
index 8dacb5e..bd71037 100644
--- a/deployments/main/docker-compose.yaml
+++ b/deployments/main/docker-compose.yaml
@@ -1,3 +1,4 @@
+version: "3"
 services:
   respondent:
     container_name: respondent