diff --git a/Dockerfile b/Dockerfile
index 420bd195..f59628c7 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM ruby:2.6.0
+FROM ruby:2.6.3
 
 ENV LANG=C.UTF-8
 ENV ENABLE_SERVICE_WORKER=true
diff --git a/Dockerfile-alpine b/Dockerfile-alpine
index a5d993f7..b916d2b1 100644
--- a/Dockerfile-alpine
+++ b/Dockerfile-alpine
@@ -1,4 +1,4 @@
-FROM ruby:2.6.0-alpine
+FROM ruby:2.6.3-alpine
 
 ENV LANG=C.UTF-8
 ENV ENABLE_SERVICE_WORKER=true