diff --git a/docs/docker/Dockerfile.bionic b/docs/docker/Dockerfile.bionic
index 2d750fe4a7..21199bd812 100644
--- a/docs/docker/Dockerfile.bionic
+++ b/docs/docker/Dockerfile.bionic
@@ -39,7 +39,8 @@ RUN apt-get install -y libnss3 \
 
 # 4. Install Firefox dependencies
 
-RUN apt-get install -y libdbus-glib-1-2
+RUN apt-get install -y libdbus-glib-1-2 \
+                       libxt6
 
 # 5. Install ffmpeg to bring in audio and video codecs necessary for playing videos in Firefox.