diff --git a/dev.yml b/dev.yml
index b84bb5ec53e316d25d23286262cc4b2107df07b8..62146828dcb7fefb384c5df5d7710f4187540516 100644
--- a/dev.yml
+++ b/dev.yml
@@ -1,4 +1,4 @@
-version: "3.9"
+version: "3.3"
 services:
   devserver:
     build:
diff --git a/docker-compose.yml b/docker-compose.yml
index 458e24253456e80951b03f9e87f3e2cae8fcbf7c..19661442781fef917b2633380deabdaacb2ebb62 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -1,4 +1,4 @@
-version: "3.9"
+version: "3.3"
 services:
   httpd:
     build: .
diff --git a/traefik.yml b/traefik.yml
index 6bc19581be76db37f189dba844b56f9ee82a81bf..d6ccaef82556712b5a55da226a351a7b4f7f67c3 100644
--- a/traefik.yml
+++ b/traefik.yml
@@ -1,4 +1,4 @@
-version: "3.9"
+version: "3.3"
 services:
   httpd:
     networks: