diff --git a/src/mess/includes/mpf1.h b/src/mess/includes/mpf1.h
index 3ee2b2b145e..577fce5c55a 100644
--- a/src/mess/includes/mpf1.h
+++ b/src/mess/includes/mpf1.h
@@ -12,7 +12,6 @@
 #include "machine/i8255.h"
 #include "machine/z80ctc.h"
 #include "machine/z80pio.h"
-#include "machine/z80sio.h"
 #include "sound/speaker.h"
 #include "sound/tms5220.h"
 
diff --git a/src/mess/includes/newbrain.h b/src/mess/includes/newbrain.h
index 7aa856a9783..0ec80ff2717 100644
--- a/src/mess/includes/newbrain.h
+++ b/src/mess/includes/newbrain.h
@@ -14,7 +14,6 @@
 #include "machine/6850acia.h"
 #include "machine/adc0808.h"
 #include "machine/z80ctc.h"
-#include "machine/z80sio.h"
 #include "machine/rescap.h"
 #include "machine/ram.h"
 #include "machine/upd765.h"
diff --git a/src/mess/includes/x1.h b/src/mess/includes/x1.h
index d713005b71f..e41ea61b791 100644
--- a/src/mess/includes/x1.h
+++ b/src/mess/includes/x1.h
@@ -11,7 +11,6 @@
 #include "cpu/z80/z80.h"
 #include "cpu/z80/z80daisy.h"
 #include "machine/z80ctc.h"
-//#include "machine/z80sio.h"
 #include "machine/z80dart.h"
 #include "machine/i8255.h"
 #include "machine/wd17xx.h"