diff --git a/docker/Dockerfile b/docker/Dockerfile
index 749b191ec2..2a2d0ba55b 100644
--- a/docker/Dockerfile
+++ b/docker/Dockerfile
@@ -37,6 +37,9 @@ RUN apt-get update && apt-get install -y \
 ENV CARGO_NET_OFFLINE=${CARGO_NET_OFFLINE}
 
 # Build dependencies that are not available as wheels, to speed up rebuilds
+RUN pip install --prefix="/install" --no-warn-script-location \
+        lxml
+
 RUN pip install --prefix="/install" --no-warn-script-location \
         cryptography