diff --git a/Dockerfile b/Dockerfile
index 3e3808f..cd599d6 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -19,8 +19,7 @@ RUN set -ex; \
 	php-curl \
     ;
 
-ENV ROUNDCUBEMAIL_VERSION=1.3.10
-
+ARG ROUNDCUBEMAIL_VERSION=1.3.10
 # Download package and extract to web volume
 RUN set -ex; \
 	fetchDeps="gnupg dirmngr ssl-cert"; \