diff --git a/Dockerfile b/Dockerfile
index a47fb69..3803aeb 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-ARG alpine_version=3.17.3
+ARG alpine_version=3.18.5
 
 FROM alpine:${alpine_version} as base
 RUN apk update && apk upgrade
diff --git a/README.md b/README.md
index 87db92c..b2bc751 100644
--- a/README.md
+++ b/README.md
@@ -26,7 +26,7 @@ Official Certhub/Lego Docker Image
 Manifest
 --------
 
-* alpine: 3.17.3
+* alpine: 3.18.5
 * certhub: v1.1.0
 * git-gau: v1.1.0
 * lego: v4.14.2