Index: Widgets/insertfile.c
--- Widgets/insertfile.c.orig
+++ Widgets/insertfile.c
@@ -26,6 +26,7 @@ SOFTWARE.
 #include <X11/Xaw/Text.h>
 #include <fcntl.h>
 #include <stdio.h>
+#include <unistd.h>
 
 Boolean
 InsertFileNamed(tw, str)