diff --git a/client.cpp b/client.cpp
index 22464bfb..574d0c6f 100644
--- a/client.cpp
+++ b/client.cpp
@@ -9,6 +9,7 @@
 #include <iostream>
 #include <sstream>
 #include <sys/time.h>
+#include <unistd.h>
 #include <deque>
 #include <vector>
 #include <algorithm>