diff --git a/scripts/selfhost-setup.sh b/scripts/selfhost-setup.sh
index 3fd4a31..1e8d4a3 100755
--- a/scripts/selfhost-setup.sh
+++ b/scripts/selfhost-setup.sh
@@ -108,6 +108,14 @@ random_secret() {
   fi
 }
 
+random_hex_secret() {
+  if command -v openssl >/dev/null 2>&1; then
+    openssl rand -hex 32 | tr -d '\n'
+  else
+    LC_ALL=C tr -dc 'a-f0-9' </dev/urandom | head -c 64
+  fi
+}
+
 env_quote() {
   local value="$1"
   value="${value//\'/\'\\\'\'}"
@@ -413,7 +421,7 @@ main() {
   minio_password="$(random_secret)"
   cookie_secret="$(random_secret)"
   jwt_secret="$(random_secret)"
-  encryption_key="$(random_secret)"
+  encryption_key="$(random_hex_secret)"
   m2m_key="$(random_secret)"
   matrix_db_password="$(random_secret)"
   matrix_turn_secret="$(random_secret)"