diff --git a/src/device/mouse.c b/src/device/mouse.c
index 7a8291e63..62e023691 100644
--- a/src/device/mouse.c
+++ b/src/device/mouse.c
@@ -347,6 +347,14 @@ mouse_subtract_coords(int *delta_x, int *delta_y, int *o_x, int *o_y,
     mouse_subtract_y(delta_y, o_y, min, max, invert, abs);
 }
 
+int
+mouse_wheel_moved(void)
+{
+    int ret = !!(atomic_load(&mouse_z));
+
+    return ret;
+}
+
 int
 mouse_moved(void)
 {
diff --git a/src/device/mouse_serial.c b/src/device/mouse_serial.c
index e8a0681f2..9a14cbe61 100644
--- a/src/device/mouse_serial.c
+++ b/src/device/mouse_serial.c
@@ -277,7 +277,7 @@ sermouse_report_ms(mouse_t *dev)
     int b = mouse_get_buttons_ex();
 
     mouse_subtract_coords(&delta_x, &delta_y, NULL, NULL, -128, 127, 0, 0);
-    mouse_subtract_z(&delta_z, -8, 7, 0);
+    mouse_subtract_z(&delta_z, -8, 7, 1);
 
     dev->buf[0] = 0x40;
     dev->buf[0] |= (((delta_y >> 6) & 0x03) << 2);
@@ -381,7 +381,12 @@ sermouse_report(mouse_t *dev)
 static void
 sermouse_transmit_report(mouse_t *dev, int from_report)
 {
-    if (mouse_capture && mouse_state_changed())
+    int changed = mouse_state_changed();
+
+    if (dev->but == 4)
+        changed |= mouse_wheel_moved();
+
+    if (mouse_capture && changed)
         sermouse_transmit(dev, sermouse_report(dev), from_report, 1);
     else {
         if (dev->prompt || dev->continuous)
diff --git a/src/include/86box/mouse.h b/src/include/86box/mouse.h
index b762810e0..93c9a744d 100644
--- a/src/include/86box/mouse.h
+++ b/src/include/86box/mouse.h
@@ -83,6 +83,7 @@ extern void            mouse_subtract_x(int *delta_x, int *o_x, int min, int max
 extern void            mouse_subtract_y(int *delta_y, int *o_y, int min, int max, int invert, int abs);
 extern void            mouse_subtract_coords(int *delta_x, int *delta_y, int *o_x, int *o_y,
                                              int min, int max, int invert, int abs);
+extern  int            mouse_wheel_moved(void);
 extern  int            mouse_moved(void);
 extern  int            mouse_state_changed(void);
 extern  int            mouse_mbut_changed(void);