diff --git a/README.md b/README.md
index b768ebe..8ec8cbb 100644
--- a/README.md
+++ b/README.md
@@ -122,7 +122,7 @@ The following environment variables can be used to change default values at comp
 - `RUNSTATEDIR` (compile): system run-time variable data (default to `/var/run`)
 - `ACMED_DEFAULT_ACCOUNTS_DIR` (compile): directory where account files are stored (default to `$VARLIBDIR/acmed/accounts`)
 - `ACMED_DEFAULT_CERT_DIR` (compile): directory where certificates and private keys are stored (default to `$VARLIBDIR/acmed/certs`)
-- `ACMED_DEFAULT_CERT_FORMAT` (compile): format for certificates and private keys files names (default to `{{name}}_{{key_type}}.{{file_type}}.{{ext}}`)
+- `ACMED_DEFAULT_CERT_FORMAT` (compile): format for certificates and private keys files names (default to `{ name }_{ key_type }.{ file_type }.{ ext }`)
 - `ACMED_DEFAULT_CONFIG_FILE` (compile): main configuration file (default to `$SYSCONFDIR/acmed/acmed.toml`)
 - `ACMED_DEFAULT_PID_FILE` (compile): PID file for the main acmed process (default to `$RUNSTATEDIR/acmed.pid`)
 - `TACD_DEFAULT_PID_FILE` (compile): PID file for the tacd process (default to `$RUNSTATEDIR/tacd.pid`)