diff --git a/Dockerfile b/Dockerfile
index 8f6eb9d..78d5d67 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -8,7 +8,7 @@
 FROM jlesage/baseimage-gui:alpine-3.9-v3.5.2
 
 # Define software versions.
-ARG FIREFOX_VERSION=62.0.3-r4
+ARG FIREFOX_VERSION=66.0.4-r0
 ARG JSONLZ4_VERSION=c4305b8
 ARG LZ4_VERSION=1.8.1.2
 #ARG PROFILE_CLEANER_VERSION=2.36