diff --git a/man/en/acmed.toml.5 b/man/en/acmed.toml.5
index 757ff11..a518053 100644
--- a/man/en/acmed.toml.5
+++ b/man/en/acmed.toml.5
@@ -773,7 +773,7 @@ args = [
 name = "http-01-echo-echo"
 type = ["challenge-http-01"]
 cmd = "echo"
-args = ["{ proof }"]
+args = ["{{ proof }}"]
 stdout = "{{ env.HTTP_ROOT | default('/var/www') }}/{{ identifier }}/.well-known/acme-challenge/{{ file_name }}"
 
 [[hook]]