diff --git a/src/impl/unix.cc b/src/impl/unix.cc
index e4ddc29..65e1b4c 100755
--- a/src/impl/unix.cc
+++ b/src/impl/unix.cc
@@ -60,8 +60,8 @@ MillisecondTimer::MillisecondTimer (const uint32_t millis)
 {
   int64_t tv_nsec = expiry.tv_nsec + (millis * 1e6);
   if (tv_nsec > 1e9) {
-    int64_t sec_diff = tv_nsec / static_cast<int> (1e6);
-    expiry.tv_nsec = tv_nsec - static_cast<int> (1e6 * sec_diff);
+    int64_t sec_diff = tv_nsec / static_cast<int> (1e9);
+    expiry.tv_nsec = tv_nsec - static_cast<int> (1e9 * sec_diff);
     expiry.tv_sec += sec_diff;
   }
 }