diff --git a/lib/session-file-helpers.js b/lib/session-file-helpers.js
index 3c22814..67cc5d3 100644
--- a/lib/session-file-helpers.js
+++ b/lib/session-file-helpers.js
@@ -100,7 +100,7 @@ var helpers = {
           options.logFn('[session-file-store] Deleting expired sessions');
           helpers.reap(options);
         }
-      }, options.reapInterval * 1000);
+      }, options.reapInterval * 1000).unref();
     }
   },
 
@@ -411,4 +411,4 @@ var helpers = {
   }
 };
 
-module.exports = helpers;
\ No newline at end of file
+module.exports = helpers;