diff --git a/sys/dev/hid/hms.c b/sys/dev/hid/hms.c
--- a/sys/dev/hid/hms.c
+++ b/sys/dev/hid/hms.c
@@ -122,6 +122,7 @@
 	hid_size_t		isize;
 	uint32_t		drift_cnt;
 	uint32_t		drift_thresh;
+	struct hid_location	wheel_loc;
 #endif
 };
 
@@ -131,6 +132,7 @@
 {
 	struct hidmap *hm = context;
 	struct hms_softc *sc = device_get_softc(hm->dev);
+	int32_t wheel;
 
 	if (len > sc->isize)
 		len = sc->isize;
@@ -140,8 +142,18 @@
 	 * to return last report data in sampling mode even after touch has
 	 * been ended.  That results in cursor drift.  Filter out such a
 	 * reports through comparing with previous one.
+	 *
+	 * Except this results in dropping consecutive mouse wheel events,
+	 * because differently from cursor movement they always move by the
+	 * same amount.  So, don't do it when there's mouse wheel movement.
 	 */
-	if (len == sc->last_irsize && memcmp(buf, sc->last_ir, len) == 0) {
+	if (sc->wheel_loc.pos != 0)
+		wheel = hid_get_data(buf, len, &sc->wheel_loc);
+	else
+		wheel = 0;
+
+	if (len == sc->last_irsize && memcmp(buf, sc->last_ir, len) == 0 &&
+	    wheel == 0) {
 		sc->drift_cnt++;
 		if (sc->drift_thresh != 0 && sc->drift_cnt >= sc->drift_thresh)
 			return;
@@ -285,9 +297,21 @@
 	/* Count number of input usages of variable type mapped to buttons */
 	for (hi = sc->hm.hid_items;
 	     hi < sc->hm.hid_items + sc->hm.nhid_items;
-	     hi++)
+	     hi++) {
 		if (hi->type == HIDMAP_TYPE_VARIABLE && hi->evtype == EV_KEY)
 			nbuttons++;
+#ifdef IICHID_SAMPLING
+		/*
+		 * Make note of which part of the report descriptor is the wheel.
+		 */
+		if (hi->type == HIDMAP_TYPE_VARIABLE &&
+		    hi->evtype == EV_REL && hi->code == REL_WHEEL) {
+			sc->wheel_loc = hi->loc;
+			/* Account for the leading Report ID byte */
+			sc->wheel_loc.pos += 8;
+		}
+#endif
+	}
 
 	/* announce information about the mouse */
 	device_printf(dev, "%d buttons and [%s%s%s%s%s] coordinates ID=%u\n",