diff --git a/nixos/modules/services/networking/ejabberd.nix b/nixos/modules/services/networking/ejabberd.nix
index 3feafc3bb3bd..72dffac9365b 100644
--- a/nixos/modules/services/networking/ejabberd.nix
+++ b/nixos/modules/services/networking/ejabberd.nix
@@ -125,6 +125,12 @@ in {
         if [ -z "$(ls -A '${cfg.spoolDir}')" ]; then
           touch "${cfg.spoolDir}/.firstRun"
         fi
+
+        if ! test -e ${cfg.spoolDir}/.erlang.cookie; then
+          touch ${cfg.spoolDir}/.erlang.cookie
+          chmod 600 ${cfg.spoolDir}/.erlang.cookie
+          dd if=/dev/random bs=16 count=1 | base64 > ${cfg.spoolDir}/.erlang.cookie
+        fi
       '';
 
       postStart = ''