diff --git a/test/msleep.cc b/test/msleep.cc
index cd989fb..5f76e49 100644
--- a/test/msleep.cc
+++ b/test/msleep.cc
@@ -10,7 +10,7 @@ void msleep(long millis)
     long const msecs_per_nsec = (1000 * 1000);
 
     long const seconds = millis / secs_per_msec;
-    long const nanos = (millis & secs_per_msec) * msecs_per_nsec;
+    long const nanos = (millis % secs_per_msec) * msecs_per_nsec;
 
     struct timespec timeout = { seconds, nanos };
     while (0 != nanosleep(&timeout, &timeout));