diff --git a/trunk/src/app/srs_app_latest_version.cpp b/trunk/src/app/srs_app_latest_version.cpp
index 322fb82bf..ba2d6fbc6 100644
--- a/trunk/src/app/srs_app_latest_version.cpp
+++ b/trunk/src/app/srs_app_latest_version.cpp
@@ -35,6 +35,7 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #include <srs_app_utility.hpp>
 #include <srs_app_uuid.hpp>
 
+#include <unistd.h>
 #include <sstream>
 using namespace std;