diff --git a/Dockerfile b/Dockerfile
index a991f5c..4f7dda5 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -11,9 +11,10 @@ ARG COMPOSER_VERSION=''
 
 ENV NVM_DIR="/home/$USERNAME/.nvm"
 
+ENV DEBIAN_FRONTEND="noninteractive"
+
 COPY start-container.sh /usr/local/bin/start-container
 
-RUN export DEBIAN_FRONTEND=noninteractive
 RUN apt-get -y update
 RUN apt-get install -y curl git 7zip php php-xml php-curl php-xml php-mbstring php-mysql php-gd
 RUN useradd --create-home --uid=$USER_UID $USERNAME