diff --git a/doc/api/process.markdown b/doc/api/process.markdown
index dafcd23bddc..68f15c2fb18 100644
--- a/doc/api/process.markdown
+++ b/doc/api/process.markdown
@@ -170,7 +170,7 @@ Example of opening standard input and listening for both events:
 
     process.stdin.setEncoding('utf8');
 
-    process.stdin.on('readable', function(chunk) {
+    process.stdin.on('readable', function() {
       var chunk = process.stdin.read();
       if (chunk !== null) {
         process.stdout.write('data: ' + chunk);