diff --git a/src/freedombone-app-xmpp b/src/freedombone-app-xmpp
index 2b99ea09370b047cbda702cbac43e4f93799b1ec..043a67a4f7b4df3c065539eff72d1bb4d019ef63 100755
--- a/src/freedombone-app-xmpp
+++ b/src/freedombone-app-xmpp
@@ -750,6 +750,7 @@ function upgrade_xmpp {
     fi
 
     # extra battery saving
+    prosody_add_module "csi_compat"
     prosody_add_module "csi_battery_saver"
 
     # remove muc logging
@@ -1000,6 +1001,7 @@ function xmpp_modules {
       echo '  "onions"; -- Enable chat via onion service';
       echo '  "mam"; -- Message archive management';
       echo '  "csi"; -- Client state indication (CSI)';
+      echo '  "csi_compat"; -- CSI for older clients';
       echo '  "csi_battery_saver"; -- Extra CSI battery saving';
       echo '  "carbons"; -- Message carbons';
       echo '  "carbons_adhoc"; -- Message carbons';