diff --git a/ngrok/Dockerfile b/ngrok/Dockerfile
index 27a17f5d..404a52c0 100644
--- a/ngrok/Dockerfile
+++ b/ngrok/Dockerfile
@@ -1,4 +1,4 @@
-FROM alpine:3.9
+FROM alpine:3.21.0
 
 RUN set -x && \
     apk add --no-cache -t .deps ca-certificates && \