diff --git a/tests/Dockerfile.hepcrawl_py3 b/tests/Dockerfile.hepcrawl_py3
index a709d7a1..c39cce51 100644
--- a/tests/Dockerfile.hepcrawl_py3
+++ b/tests/Dockerfile.hepcrawl_py3
@@ -3,7 +3,7 @@ FROM python:3-slim
 WORKDIR /usr/src/app
 
 RUN apt-get update \
-  && apt-get install --no-install-recommends -y build-essential \
+  && apt-get install --no-install-recommends -y build-essential libxslt1-dev zlib1g \
   && rm -rf /var/lib/apt/lists
 
 COPY . .