diff --git a/lib/json.js b/lib/json.js
index a3428ef..fd829dd 100755
--- a/lib/json.js
+++ b/lib/json.js
@@ -190,7 +190,7 @@ function printHelp() {
     w('In-place editing:');
     w('  Use "-I, --in-place" to edit a file in place:');
     w('     $ json -I -f config.json  # reformat');
-    w('     $ json -I -f config.json -c \'this.logLevel="debug"\' # add field');
+    w('     $ json -I -f config.json -e \'this.logLevel="debug"\' # add field');
     w('');
     w('Pretty-printing:');
     w('  Output is "jsony" by default: 2-space indented JSON, except a');