diff --git a/debian/postinst b/debian/postinst
index 4c40d718..c81160b2 100644
--- a/debian/postinst
+++ b/debian/postinst
@@ -14,7 +14,8 @@ do_configure() {
   # Replace RANDOMID with a random hash to invalidate
   # old cache ... we generate this locally on each machine
   # to avoid leaking stuff like the version
-  RANDOMID=$(openssl rand -hex 4)
+  # https://stackoverflow.com/questions/94445/using-openssl-what-does-unable-to-write-random-state-mean
+  RANDOMID=$(RANDFILE=.rnd openssl rand -hex 4)
   sed -i "s/RANDOMID/$RANDOMID/g" /usr/share/yunohost/admin/index.html
 }