diff --git a/debian/python3-osm-mon.postinst b/debian/python3-osm-mon.postinst
index 3fa26dc..89cd2b3 100644
--- a/debian/python3-osm-mon.postinst
+++ b/debian/python3-osm-mon.postinst
@@ -16,4 +16,5 @@
 pip3 install bottle==0.12.*
 pip3 install peewee==3.1.*
 pip3 install pyyaml==3.*
+pip3 install prometheus_client==0.4.*
 echo "Installation of python dependencies finished"
\ No newline at end of file