src/Align/find-tandem.cc |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/src/Align/find-tandem.cc b/src/Align/find-tandem.cc
index ddf1cab..a29e21e 100644
--- a/src/Align/find-tandem.cc
+++ b/src/Align/find-tandem.cc
@@ -7,6 +7,7 @@
 #include <vector>
 #include <ctime>
 #include <sys/time.h>
+#include <unistd.h>
 using namespace std;
 
 const int OFFSET_TABLE_SIZE = 100;