diff --git a/Dockerfile b/Dockerfile
index 75f7be5..8c2ff9c 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -2,7 +2,7 @@
 
 ARG ALPINE_VERSION=3.18
 
-FROM alpine:$ALPINE_VERSION
+FROM alpine:${ALPINE_VERSION}
 
 RUN apk add --no-cache curl jq