diff --git a/bin/seagl-setup-app b/bin/seagl-setup-app
index 2b44b08..7ee23ef 100755
--- a/bin/seagl-setup-app
+++ b/bin/seagl-setup-app
@@ -26,7 +26,7 @@ elif [ $1 == nextcloud ]; then
 	nextcloud --userid 2024laptops --apppassword "$(jq .nextcloudAppPassword < /var/lib/seagl/config-data.json)" --isvfsenabled 0 --serverurl 'https://cloud.seagl.org/'
 	start_and_link_app com.nextcloud.desktopclient.nextcloud
 elif [ $1 == firefox ]; then
-	sed -i "s;AV_TEST_RESULTS_PLACEHOLDER;$(jq .avTestResultsSheetURL < /var/lib/seagl/config-data.json);" /etc/firefox/policies/policies.json
+	sudo sed -i "s;AV_TEST_RESULTS_PLACEHOLDER;$(jq .avTestResultsSheetURL < /var/lib/seagl/config-data.json);" /etc/firefox/policies/policies.json
 	start_and_link_app org.mozilla.firefox
 else
 	echo fatal: application to be set up must be one of obs, nextcloud, firefox