diff --git a/Dockerfile b/Dockerfile
index 78e772a..d40a87c 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -13,4 +13,8 @@ RUN mkdir -p /srv/tftp && \
 
 EXPOSE 69/udp
 
-CMD ["/usr/sbin/in.tftpd", "--ipv4", "--foreground", "--verbose", "--address", "0.0.0.0:69", "--secure", "--create", "-vvv", "/srv/tftp"]
+ENV TFTP_PORT=69
+ENV TFTP_DIR=/srv/tftp
+
+CMD bash -c "/usr/sbin/in.tftpd --ipv4 --foreground --verbose --address 0.0.0.0:${TFTP_PORT} --secure --create -vvv ${TFTP_DIR} 2>&1"
+