3 files changed, 3 insertions, 0 deletions
diff --git a/libXt/src/Error.c b/libXt/src/Error.c
index edec46e61..b2170557a 100644
--- a/libXt/src/Error.c
+++ b/libXt/src/Error.c
@@ -74,6 +74,7 @@ in this Software without prior written authorization from The Open Group.
 #include "IntrinsicI.h"
 #include <stdio.h>
 #include <stdlib.h>
+#include <unistd.h>
 
 /* The error handlers in the application context aren't used since we can't
    come up with a uniform way of using them.  If you can, define
diff --git a/libXt/src/Selection.c b/libXt/src/Selection.c
index 6040527bc..841e25a9e 100644
--- a/libXt/src/Selection.c
+++ b/libXt/src/Selection.c
@@ -76,6 +76,7 @@ in this Software without prior written authorization from The Open Group.
 #include "SelectionI.h"
 #include <X11/Xatom.h>
 #include <stdio.h>
+#include <unistd.h>
 
 void _XtSetDefaultSelectionTimeout(
 	unsigned long *timeout)
diff --git a/libXt/src/Shell.c b/libXt/src/Shell.c
index e0580ee4b..c0003a2a1 100644
--- a/libXt/src/Shell.c
+++ b/libXt/src/Shell.c
@@ -89,6 +89,7 @@ in this Software without prior written authorization from The Open Group.
 #endif
 #include <stdio.h>
 #include <stdlib.h>
+#include <unistd.h>
 
 #ifdef EDITRES
 #include <X11/Xmu/Editres.h>