diff --git a/src/qm_mpdcom.cpp b/src/qm_mpdcom.cpp
index 5659c9b..a949798 100644
--- a/src/qm_mpdcom.cpp
+++ b/src/qm_mpdcom.cpp
@@ -19,6 +19,8 @@
  *  along with this program. If not, see http://www.gnu.org/licenses/.
  */
 
+#include <unistd.h>
+
 #include "qm_mpdcom.h"
 
 qm_mpdCom::qm_mpdCom()