diff --git a/tests/limited-io.hpp b/tests/limited-io.hpp
index cb81247..92aef02 100644
--- a/tests/limited-io.hpp
+++ b/tests/limited-io.hpp
@@ -1,11 +1,12 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /**
- * Copyright (c) 2014  Regents of the University of California,
- *                     Arizona Board of Regents,
- *                     Colorado State University,
- *                     University Pierre & Marie Curie, Sorbonne University,
- *                     Washington University in St. Louis,
- *                     Beijing Institute of Technology
+ * Copyright (c) 2014,  Regents of the University of California,
+ *                      Arizona Board of Regents,
+ *                      Colorado State University,
+ *                      University Pierre & Marie Curie, Sorbonne University,
+ *                      Washington University in St. Louis,
+ *                      Beijing Institute of Technology,
+ *                      The University of Memphis
  *
  * This file is part of NFD (Named Data Networking Forwarding Daemon).
  * See AUTHORS.md for complete list of NFD authors and contributors.
@@ -20,7 +21,7 @@
  *
  * You should have received a copy of the GNU General Public License along with
  * NFD, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
- **/
+ */
 
 #ifndef NFD_TESTS_LIMITED_IO_HPP
 #define NFD_TESTS_LIMITED_IO_HPP
@@ -33,7 +34,7 @@
 
 /** \brief provides IO operations limit and/or time limit for unit testing
  */
-class LimitedIo
+class LimitedIo : noncopyable
 {
 public:
   LimitedIo();
@@ -41,7 +42,7 @@
   /// indicates why .run returns
   enum StopReason
   {
-    /// g_io.run() runs normally because there's no work to do
+    /// g_io.run() returns normally because there's no work to do
     NO_WORK,
     /// .afterOp() has been invoked nOpsLimit times
     EXCEED_OPS,
@@ -66,6 +67,16 @@
   const std::exception&
   getLastException() const;
 
+  /** \brief defer for specified duration
+   *
+   *  equivalent to .run(UNLIMITED_OPS, d)
+   */
+  void
+  defer(const time::nanoseconds& d)
+  {
+    this->run(UNLIMITED_OPS, d);
+  }
+
 private:
   void
   afterTimeout();