diff --git a/Dockerfile b/Dockerfile
index 2014c62..ba2ec96 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -5,7 +5,7 @@
 #
 
 # Pull base image.
-FROM jlesage/baseimage-gui:alpine-3.8-v3.5.1
+FROM jlesage/baseimage-gui:alpine-3.9-v3.5.1
 
 # Define software versions.
 ARG FIREFOX_VERSION=61.0.1-r0