diff --git a/src/evdev.c b/src/evdev.c
index 6ab68ae3..07259741 100644
--- a/src/evdev.c
+++ b/src/evdev.c
@@ -958,6 +958,7 @@ fallback_process_relative(struct fallback_dispatch *dispatch,
 {
 	struct normalized_coords wheel_degrees = { 0.0, 0.0 };
 	struct discrete_coords discrete = { 0.0, 0.0 };
+	enum libinput_pointer_axis_source source;
 
 	if (fallback_reject_relative(device, e, time))
 		return;
@@ -980,11 +981,16 @@ fallback_process_relative(struct fallback_dispatch *dispatch,
 		wheel_degrees.y = -1 * e->value *
 					device->scroll.wheel_click_angle.x;
 		discrete.y = -1 * e->value;
+
+		source = device->scroll.is_tilt.vertical ?
+				LIBINPUT_POINTER_AXIS_SOURCE_WHEEL_TILT:
+				LIBINPUT_POINTER_AXIS_SOURCE_WHEEL;
+
 		evdev_notify_axis(
 			device,
 			time,
 			AS_MASK(LIBINPUT_POINTER_AXIS_SCROLL_VERTICAL),
-			LIBINPUT_POINTER_AXIS_SOURCE_WHEEL,
+			source,
 			&wheel_degrees,
 			&discrete);
 		break;
@@ -993,11 +999,16 @@ fallback_process_relative(struct fallback_dispatch *dispatch,
 		wheel_degrees.x = e->value *
 					device->scroll.wheel_click_angle.y;
 		discrete.x = e->value;
+
+		source = device->scroll.is_tilt.horizontal ?
+				LIBINPUT_POINTER_AXIS_SOURCE_WHEEL_TILT:
+				LIBINPUT_POINTER_AXIS_SOURCE_WHEEL;
+
 		evdev_notify_axis(
 			device,
 			time,
 			AS_MASK(LIBINPUT_POINTER_AXIS_SCROLL_HORIZONTAL),
-			LIBINPUT_POINTER_AXIS_SOURCE_WHEEL,
+			source,
 			&wheel_degrees,
 			&discrete);
 		break;
@@ -2110,6 +2121,21 @@ evdev_read_wheel_click_props(struct evdev_device *device)
 	return angles;
 }
 
+static inline struct wheel_tilt_flags
+evdev_read_wheel_tilt_props(struct evdev_device *device)
+{
+	struct wheel_tilt_flags flags;
+
+	flags.vertical = parse_udev_flag(device,
+					 device->udev_device,
+					 "MOUSE_WHEEL_TILT_VERTICAL");
+
+	flags.horizontal = parse_udev_flag(device,
+					 device->udev_device,
+					 "MOUSE_WHEEL_TILT_HORIZONTAL");
+	return flags;
+}
+
 static inline int
 evdev_get_trackpoint_dpi(struct evdev_device *device)
 {
@@ -2848,6 +2874,7 @@ evdev_device_create(struct libinput_seat *seat,
 	device->scroll.direction = 0;
 	device->scroll.wheel_click_angle =
 		evdev_read_wheel_click_props(device);
+	device->scroll.is_tilt = evdev_read_wheel_tilt_props(device);
 	device->model_flags = evdev_read_model_flags(device);
 	device->dpi = DEFAULT_MOUSE_DPI;
 
diff --git a/src/evdev.h b/src/evdev.h
index 7ad3dfd8..95cde8bc 100644
--- a/src/evdev.h
+++ b/src/evdev.h
@@ -198,6 +198,8 @@ struct evdev_device {
 
 		/* angle per REL_WHEEL click in degrees */
 		struct wheel_angle wheel_click_angle;
+
+		struct wheel_tilt_flags is_tilt;
 	} scroll;
 
 	struct {
diff --git a/src/libinput-private.h b/src/libinput-private.h
index 0c75b3aa..40cc9269 100644
--- a/src/libinput-private.h
+++ b/src/libinput-private.h
@@ -94,6 +94,11 @@ struct phys_coords {
 	double y;
 };
 
+/* A pair of tilt flags */
+struct wheel_tilt_flags {
+	bool vertical, horizontal;
+};
+
 struct tablet_axes {
 	struct device_coords point;
 	struct normalized_coords delta;
diff --git a/src/libinput.h b/src/libinput.h
index 86bfeaf4..fdbba3c1 100644
--- a/src/libinput.h
+++ b/src/libinput.h
@@ -259,6 +259,12 @@ enum libinput_pointer_axis_source {
 	 * The event is caused by the motion of some device.
 	 */
 	LIBINPUT_POINTER_AXIS_SOURCE_CONTINUOUS,
+	/**
+	 * The event is caused by the tilting of a mouse wheel rather than
+	 * its rotation. This method is commonly used on mice without
+	 * separate horizontal scroll wheels.
+	 */
+	LIBINPUT_POINTER_AXIS_SOURCE_WHEEL_TILT,
 };
 
 /**
@@ -1285,6 +1291,15 @@ libinput_event_pointer_get_axis_value(struct libinput_event_pointer *event,
  * The coordinate system is identical to the cursor movement, i.e. a
  * scroll value of 1 represents the equivalent relative motion of 1.
  *
+ * If the source is @ref LIBINPUT_POINTER_AXIS_SOURCE_WHEEL_TILT, no
+ * terminating event is guaranteed (though it may happen).
+ * Scrolling is in discrete steps and there is no physical equivalent for
+ * the value returned here. For backwards compatibility, the value returned
+ * by this function is identical to a single mouse wheel rotation by this
+ * device (see the documentation for @ref LIBINPUT_POINTER_AXIS_SOURCE_WHEEL
+ * above). Callers should not use this value but instead exclusively refer
+ * to the value returned by libinput_event_pointer_get_axis_value_discrete().
+ *
  * For pointer events that are not of type @ref LIBINPUT_EVENT_POINTER_AXIS,
  * this function returns 0.
  *
diff --git a/test/Makefile.am b/test/Makefile.am
index 5980dba0..0d54dab6 100644
--- a/test/Makefile.am
+++ b/test/Makefile.am
@@ -36,6 +36,7 @@ liblitest_la_SOURCES = \
 	litest-device-nexus4-touch-screen.c \
 	litest-device-magic-trackpad.c \
 	litest-device-mouse.c \
+	litest-device-mouse-wheel-tilt.c \
 	litest-device-mouse-roccat.c \
 	litest-device-mouse-low-dpi.c \
 	litest-device-mouse-wheel-click-angle.c \
diff --git a/test/litest-device-mouse-wheel-tilt.c b/test/litest-device-mouse-wheel-tilt.c
new file mode 100644
index 00000000..2a63469c
--- /dev/null
+++ b/test/litest-device-mouse-wheel-tilt.c
@@ -0,0 +1,76 @@
+/*
+ * Copyright © 2016 Red Hat, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#if HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "litest.h"
+#include "litest-int.h"
+
+static void litest_mouse_setup(void)
+{
+	struct litest_device *d = litest_create_device(LITEST_MOUSE_WHEEL_TILT);
+	litest_set_current_device(d);
+}
+
+static struct input_id input_id = {
+	.bustype = 0x3,
+	.vendor = 0x17ef,
+	.product = 0x6019,
+};
+
+static int events[] = {
+	EV_KEY, BTN_LEFT,
+	EV_KEY, BTN_RIGHT,
+	EV_KEY, BTN_MIDDLE,
+	EV_REL, REL_X,
+	EV_REL, REL_Y,
+	EV_REL, REL_WHEEL,
+	EV_REL, REL_HWHEEL,
+	-1 , -1,
+};
+
+static const char udev_rule[] =
+"ACTION==\"remove\", GOTO=\"wheel_wheel_tilt_end\"\n"
+"KERNEL!=\"event*\", GOTO=\"wheel_wheel_tilt_end\"\n"
+"\n"
+"ATTRS{name}==\"litest Wheel Tilt Mouse*\",\\\n"
+"    ENV{MOUSE_WHEEL_TILT_HORIZONTAL}=\"1\",\\\n"
+"    ENV{MOUSE_WHEEL_TILT_VERTICAL}=\"1\"\n"
+"\n"
+"LABEL=\"wheel_wheel_tilt_end\"";
+
+struct litest_test_device litest_mouse_wheel_tilt_device = {
+	.type = LITEST_MOUSE_WHEEL_TILT,
+	.features = LITEST_RELATIVE | LITEST_BUTTON | LITEST_WHEEL,
+	.shortname = "mouse-wheel-tilt",
+	.setup = litest_mouse_setup,
+	.interface = NULL,
+
+	.name = "Wheel Tilt Mouse",
+	.id = &input_id,
+	.absinfo = NULL,
+	.events = events,
+	.udev_rule = udev_rule,
+};
diff --git a/test/litest.c b/test/litest.c
index 10993d9f..b3e7ba3d 100644
--- a/test/litest.c
+++ b/test/litest.c
@@ -407,6 +407,7 @@ extern struct litest_test_device litest_calibrated_touchscreen_device;
 extern struct litest_test_device litest_acer_hawaii_keyboard_device;
 extern struct litest_test_device litest_acer_hawaii_touchpad_device;
 extern struct litest_test_device litest_synaptics_rmi4_device;
+extern struct litest_test_device litest_mouse_wheel_tilt_device;
 
 struct litest_test_device* devices[] = {
 	&litest_synaptics_clickpad_device,
@@ -468,6 +469,7 @@ struct litest_test_device* devices[] = {
 	&litest_acer_hawaii_keyboard_device,
 	&litest_acer_hawaii_touchpad_device,
 	&litest_synaptics_rmi4_device,
+	&litest_mouse_wheel_tilt_device,
 	NULL,
 };
 
diff --git a/test/litest.h b/test/litest.h
index ccda9a42..e6d35a90 100644
--- a/test/litest.h
+++ b/test/litest.h
@@ -227,6 +227,7 @@ enum litest_device_type {
 	LITEST_ACER_HAWAII_KEYBOARD,
 	LITEST_ACER_HAWAII_TOUCHPAD,
 	LITEST_SYNAPTICS_RMI4,
+	LITEST_MOUSE_WHEEL_TILT,
 };
 
 enum litest_device_feature {
diff --git a/test/test-pointer.c b/test/test-pointer.c
index a706c001..b5ac1585 100644
--- a/test/test-pointer.c
+++ b/test/test-pointer.c
@@ -546,6 +546,33 @@ out:
 	return angle;
 }
 
+static enum libinput_pointer_axis_source
+wheel_source(struct litest_device *dev, int which)
+{
+	struct udev_device *d;
+	bool is_tilt = false;
+
+	d = libinput_device_get_udev_device(dev->libinput_device);
+	litest_assert_ptr_notnull(d);
+
+	switch(which) {
+	case REL_WHEEL:
+		is_tilt = !!udev_device_get_property_value(d, "MOUSE_WHEEL_TILT_VERTICAL");
+		break;
+	case REL_HWHEEL:
+		is_tilt = !!udev_device_get_property_value(d, "MOUSE_WHEEL_TILT_HORIZONTAL");
+		break;
+	default:
+		litest_abort_msg("Invalid source axis %d\n", which);
+		break;
+	}
+
+	udev_device_unref(d);
+	return is_tilt ?
+		LIBINPUT_POINTER_AXIS_SOURCE_WHEEL_TILT :
+		LIBINPUT_POINTER_AXIS_SOURCE_WHEEL;
+}
+
 static void
 test_wheel_event(struct litest_device *dev, int which, int amount)
 {
@@ -553,10 +580,12 @@ test_wheel_event(struct litest_device *dev, int which, int amount)
 	struct libinput_event *event;
 	struct libinput_event_pointer *ptrev;
 	enum libinput_pointer_axis axis;
+	enum libinput_pointer_axis_source source;
 
 	double scroll_step, expected, discrete;
 
 	scroll_step = wheel_click_angle(dev, which);
+	source = wheel_source(dev, which);
 	expected = amount * scroll_step;
 	discrete = amount;
 
@@ -576,10 +605,9 @@ test_wheel_event(struct litest_device *dev, int which, int amount)
 	axis = (which == REL_WHEEL) ?
 				LIBINPUT_POINTER_AXIS_SCROLL_VERTICAL :
 				LIBINPUT_POINTER_AXIS_SCROLL_HORIZONTAL;
+
 	event = libinput_get_event(li);
-	ptrev = litest_is_axis_event(event,
-				     axis,
-				     LIBINPUT_POINTER_AXIS_SOURCE_WHEEL);
+	ptrev = litest_is_axis_event(event, axis, source);
 
 	litest_assert_double_eq(
 			libinput_event_pointer_get_axis_value(ptrev, axis),
@@ -693,7 +721,7 @@ START_TEST(pointer_scroll_has_axis_invalid)
 	event = libinput_get_event(li);
 	pev = litest_is_axis_event(event,
 				   LIBINPUT_POINTER_AXIS_SCROLL_VERTICAL,
-				   LIBINPUT_POINTER_AXIS_SOURCE_WHEEL);
+				   0);
 
 	ck_assert_int_eq(libinput_event_pointer_has_axis(pev, -1), 0);
 	ck_assert_int_eq(libinput_event_pointer_has_axis(pev, 2), 0);
diff --git a/tools/event-debug.c b/tools/event-debug.c
index d7d20188..a3e460a2 100644
--- a/tools/event-debug.c
+++ b/tools/event-debug.c
@@ -377,6 +377,9 @@ print_pointer_axis_event(struct libinput_event *ev)
 	case LIBINPUT_POINTER_AXIS_SOURCE_CONTINUOUS:
 		source = "continuous";
 		break;
+	case LIBINPUT_POINTER_AXIS_SOURCE_WHEEL_TILT:
+		source = "tilt";
+		break;
 	}
 
 	if (libinput_event_pointer_has_axis(p,