diff --git a/Dockerfile b/Dockerfile
index 4b0016f358..42f3f7242e 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,6 +1,6 @@
 FROM ubuntu:22.04 as build
 
-ENV MIX_ENV=prod \
+ARG MIX_ENV=prod \
     OAUTH_CONSUMER_STRATEGIES="twitter facebook google microsoft slack github keycloak:ueberauth_keycloak_strategy"
 
 WORKDIR /src