diff --git a/lib/commands/config.js b/lib/commands/config.js
index <HASH>..<HASH> 100644
--- a/lib/commands/config.js
+++ b/lib/commands/config.js
@@ -65,6 +65,11 @@ cmd.handler = function(argv) {
   if (argv.key.length === 0)
     return log.info(prettyConfig(loadConfig(argv.all)));
 
+  // sugar: notice user that use ':' instead of '.'
+  if (argv.key.includes('.') && !argv.key.includes(':'))
+    return log.printf('Key should use colon(:) as the delimiter, do you mean %s?',
+      chalk.yellow(argv.key.replace(/\./g, ':')));
+
   const v = nconf.get(argv.key);
 
   // delete
Notice user to use ":" in config key.