diff --git a/playground/Dockerfile b/playground/Dockerfile
index 568fc16..4e310cb 100644
--- a/playground/Dockerfile
+++ b/playground/Dockerfile
@@ -1,4 +1,4 @@
-from alpine:3.9 as builder
+from alpine:3.11 as builder
 
 RUN apk add --no-cache \
         git make
diff --git a/ssl/Dockerfile b/ssl/Dockerfile
index 7b6e64f..6abb036 100644
--- a/ssl/Dockerfile
+++ b/ssl/Dockerfile
@@ -1,4 +1,4 @@
-FROM alpine:3.9
+FROM alpine:3.11
 
 ARG VCS_REF