diff --git a/src/display.h b/src/display.h
index 09a0775..1fea3a8 100644
--- a/src/display.h
+++ b/src/display.h
@@ -69,6 +69,8 @@
 
 .- */
 
+#include <X11/Xlib.h>
+
 /*---------------------------------------------------------------------------
         Data type definitions - require config.h, machdep.h, cpu.h
   ---------------------------------------------------------------------------*/
diff --git a/src/emulator.c b/src/emulator.c
index b50b597..290ba24 100644
--- a/src/emulator.c
+++ b/src/emulator.c
@@ -118,8 +118,6 @@ static char rcs_id[] = "$Id: emulator.c,v 4.1 2000/12/11 09:54:19 cibrario Rel $
 #include <unistd.h>
 #include <sys/time.h>
 
-#include <X11/Xlib.h>
-
 #include "config.h"
 #include "machdep.h"
 #include "cpu.h"
diff --git a/src/monitor.c b/src/monitor.c
index 6fe41f9..54d9ead 100644
--- a/src/monitor.c
+++ b/src/monitor.c
@@ -76,8 +76,6 @@ static char rcs_id[] = "$Id: monitor.c,v 4.1 2000/12/11 09:54:19 cibrario Rel $"
 #include <signal.h>
 #include <errno.h>
 
-#include <X11/Xlib.h>
-
 #include "config.h"
 #include "machdep.h"
 #include "cpu.h"