diff --git a/lib/svgo/coa.js b/lib/svgo/coa.js
index 62404fc34..62abcfff6 100644
--- a/lib/svgo/coa.js
+++ b/lib/svgo/coa.js
@@ -47,7 +47,10 @@ export default function makeProgram(program) {
       '-p, --precision <INTEGER>',
       'Set number of digits in the fractional part, overrides plugins params',
     )
-    .option('--config <CONFIG>', 'Custom config file, only .js is supported')
+    .option(
+      '--config <CONFIG>',
+      'Custom config file, only .js, .mjs, and .cjs is supported',
+    )
     .option(
       '--datauri <FORMAT>',
       'Output as Data URI string (base64), URI encoded (enc) or unencoded (unenc)',