diff --git a/.ci.yml b/.ci.yml
index 0a27887..b2276e0 100644
--- a/.ci.yml
+++ b/.ci.yml
@@ -3,7 +3,7 @@ image: debian:bullseye
 before_script:
   - apt -qqy update > /dev/null
   - apt -qqy install --no-install-recommends screen sysstat gnuplot-nox python3 python3-pip stress coreutils > /dev/null
-  - pip install plotext
+  - pip install numpy plotext
   - ln -s $(realpath sargraph.py) /usr/bin/sargraph
 
 simple_test: