diff --git a/lib/inputs/input_file.js b/lib/inputs/input_file.js
index e68ac46..0ac8fbd 100644
--- a/lib/inputs/input_file.js
+++ b/lib/inputs/input_file.js
@@ -65,7 +65,7 @@ InputFile.prototype.monitorFile = function(dir, filename, start_index) {
     if (err) {
       this.emit('error', err);
     }
-  }, start_index);
+  }.bind(this), start_index);
 
 };