diff --git a/celestia/src/celestia/kde/kdeapp.cpp b/celestia/src/celestia/kde/kdeapp.cpp

index 5e40770..c16840d 100644

--- a/celestia/src/celestia/kde/kdeapp.cpp

+++ b/celestia/src/celestia/kde/kdeapp.cpp

@@ -16,6 +16,7 @@

  ***************************************************************************/

+#include <unistd.h>

 #include <libintl.h>

 #include <fstream>

 #include <sstream>