diff --git a/debian/gitlab.postinst b/debian/gitlab.postinst
index 71468a0875..45f7b125d4 100755
--- a/debian/gitlab.postinst
+++ b/debian/gitlab.postinst
@@ -95,6 +95,9 @@ runuser -u ${gitlab_user} -- sh -c "if ! gem list -i -v 1.2.2 "^ipaddr$" >/dev/n
 runuser -u ${gitlab_user} -- sh -c "if ! gem list -i -v 2.3.2 "^deckar01-task_list$" >/dev/null; then gem install -v 2.3.2 deckar01-task_list; fi"
 runuser -u ${gitlab_user} -- sh -c "if ! gem list -i -v 0.53.0 "^google-api-client$" >/dev/null; then gem install -v 0.53.0 google-api-client; fi"
 
+# Uninstall rack 3.x
+runuser -u ${gitlab_user} -- sh -c "if ! gem list -i -v '~>3.0' "^rack$" >/dev/null; then gem uninstall -v '~>3.0' rack; fi"
+
 #######################################################################
 # update Gemfile.lock and yarn.lock, always
 #######################################################################