diff --git a/ci/config.sh b/ci/config.sh
index d3110c7ca691fb9f568585388fa83b667b7b24c0..9dc53665f263c80384f91d473a4403d41483b24f 100644
--- a/ci/config.sh
+++ b/ci/config.sh
@@ -105,6 +105,7 @@ extra_package singletons
 extra_package servant
 extra_package hgmp
 extra_package Agda 2.6.1.3
+extra_package mmark
 
 # Build-tool packages
 build_tool_package alex