diff --git a/LCS/Common/test/tTimer.cc b/LCS/Common/test/tTimer.cc
index e75835601809a58a967b016e7d0c6bd723a91a3c..86ee6e408c225ae0ce714ab1b0cdd4e816c462a9 100644
--- a/LCS/Common/test/tTimer.cc
+++ b/LCS/Common/test/tTimer.cc
@@ -25,7 +25,7 @@
 
 #include <cmath>
 #include <iostream>
-
+#include <unistd.h>
 #include <Common/Timer.h>
 
 double a = 1;