diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 65e52fc2051cdd529a70b0f5c55073882d2a94a9..2e0e91a79338481d5e0e8db6b25fc1fd1676c5f2 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -21,7 +21,7 @@ build_msp430fr5969lp:
   script:
   - dpkg --add-architecture i386
   - apt-get update -qy
-  - apt-get install -y build-essential curl libc6:i386 libgcc1:i386 libstdc++6:i386
+  - apt-get install -y build-essential curl libc6:i386 libgcc1:i386 libstdc++6:i386 zlib1g:i386
   - curl -s https://ess.cs.uos.de/static/.gitlab-ci/msp430-gcc-full-linux-4.9.1.tar.xz | tar -C /opt -xJf -
   - mkdir -p build
   - make -B arch=msp430fr5969lp app=donothing