diff --git a/Dockerfile b/Dockerfile
index 8250aeb..c2bca34 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,6 @@
-FROM alpine:latest
+ARG ALPINE_VERSION=3.14
+
+FROM alpine:${ALPINE_VERSION}
 
 ARG ZT_VERSION=1.6.5-r0