diff --git a/src/Input.h b/src/Input.h
index 29ab0b9..b07b3b9 100644
--- a/src/Input.h
+++ b/src/Input.h
@@ -127,11 +127,14 @@ typedef struct _SS_HSCROLL_PACKET {
 typedef struct _SS_TOUCH_PACKET {
     NV_INPUT_HEADER header;
     uint8_t eventType;
-    uint8_t zero[3]; // Alignment/reserved
+    uint8_t zero[1]; // Alignment/reserved
+    uint16_t rotation;
     uint32_t pointerId;
     netfloat x;
     netfloat y;
     netfloat pressureOrDistance;
+    netfloat contactAreaMajor;
+    netfloat contactAreaMinor;
 } SS_TOUCH_PACKET, *PSS_TOUCH_PACKET;
 
 #define SS_PEN_MAGIC 0x55000003
@@ -147,6 +150,8 @@ typedef struct _SS_PEN_PACKET {
     uint16_t rotation;
     uint8_t tilt;
     uint8_t zero2[1];
+    netfloat contactAreaMajor;
+    netfloat contactAreaMinor;
 } SS_PEN_PACKET, *PSS_PEN_PACKET;
 
 #define SS_CONTROLLER_ARRIVAL_MAGIC 0x55000004
diff --git a/src/InputStream.c b/src/InputStream.c
index 3bc75a2..4855965 100644
--- a/src/InputStream.c
+++ b/src/InputStream.c
@@ -1216,7 +1216,8 @@ int LiSendHScrollEvent(signed char scrollClicks) {
     return LiSendHighResHScrollEvent(scrollClicks * LI_WHEEL_DELTA);
 }
 
-int LiSendTouchEvent(uint8_t eventType, uint32_t pointerId, float x, float y, float pressureOrDistance) {
+int LiSendTouchEvent(uint8_t eventType, uint32_t pointerId, float x, float y, float pressureOrDistance,
+                     float contactAreaMajor, float contactAreaMinor, uint16_t rotation) {
     PPACKET_HOLDER holder;
     int err;
 
@@ -1244,10 +1245,13 @@ int LiSendTouchEvent(uint8_t eventType, uint32_t pointerId, float x, float y, fl
     holder->packet.touch.header.magic = LE32(SS_TOUCH_MAGIC);
     holder->packet.touch.eventType = eventType;
     holder->packet.touch.pointerId = LE32(pointerId);
+    holder->packet.touch.rotation = LE16(rotation);
     memset(holder->packet.touch.zero, 0, sizeof(holder->packet.touch.zero));
     floatToNetfloat(x, holder->packet.touch.x);
     floatToNetfloat(y, holder->packet.touch.y);
     floatToNetfloat(pressureOrDistance, holder->packet.touch.pressureOrDistance);
+    floatToNetfloat(contactAreaMajor, holder->packet.touch.contactAreaMajor);
+    floatToNetfloat(contactAreaMinor, holder->packet.touch.contactAreaMinor);
 
     err = LbqOfferQueueItem(&packetQueue, holder, &holder->entry);
     if (err != LBQ_SUCCESS) {
@@ -1261,6 +1265,7 @@ int LiSendTouchEvent(uint8_t eventType, uint32_t pointerId, float x, float y, fl
 
 int LiSendPenEvent(uint8_t eventType, uint8_t toolType, uint8_t penButtons,
                    float x, float y, float pressureOrDistance,
+                   float contactAreaMajor, float contactAreaMinor,
                    uint16_t rotation, uint8_t tilt) {
     PPACKET_HOLDER holder;
     int err;
@@ -1298,6 +1303,8 @@ int LiSendPenEvent(uint8_t eventType, uint8_t toolType, uint8_t penButtons,
     holder->packet.pen.rotation = LE16(rotation);
     holder->packet.pen.tilt = tilt;
     memset(holder->packet.pen.zero2, 0, sizeof(holder->packet.pen.zero2));
+    floatToNetfloat(contactAreaMajor, holder->packet.pen.contactAreaMajor);
+    floatToNetfloat(contactAreaMinor, holder->packet.pen.contactAreaMinor);
 
     err = LbqOfferQueueItem(&packetQueue, holder, &holder->entry);
     if (err != LBQ_SUCCESS) {
diff --git a/src/Limelight.h b/src/Limelight.h
index a658b82..e890dbe 100644
--- a/src/Limelight.h
+++ b/src/Limelight.h
@@ -593,17 +593,30 @@ int LiSendMouseMoveAsMousePositionEvent(short deltaX, short deltaY, short refere
 
 // This function allows multi-touch input to be sent directly to Sunshine hosts. The x and y values
 // are normalized device coordinates stretching top-left corner (0.0, 0.0) to bottom-right corner
-// (1.0, 1.0) of the video area. Pressure is a 0.0 to 1.0 range value from min to max pressure.
+// (1.0, 1.0) of the video area.
 //
-// Sending a down/move event with a pressure of 0.0 indicates the actual pressure is unknown.
+// Pointer ID is an opaque ID that must uniquely identify each active touch on screen. It must
+// remain constant through any down/up/move/cancel events involved in a single touch interaction.
+//
+// Rotation is in degrees from vertical in Y dimension (parallel to screen, 0..360). If rotation is
+// unknown, pass LI_ROT_UNKNOWN.
+//
+// Pressure is a 0.0 to 1.0 range value from min to max pressure. Sending a down/move event with
+// a pressure of 0.0 indicates the actual pressure is unknown.
 //
 // For hover events, the pressure value is treated as a 1.0 to 0.0 range of distance from the touch
 // surface where 1.0 is the farthest measurable distance and 0.0 is actually touching the display
 // (which is invalid for a hover event). Reporting distance 0.0 for a hover event indicates the
 // actual distance is unknown.
 //
-// Pointer ID is an opaque ID that must uniquely identify each active touch on screen. It must
-// remain constant through any down/up/move/cancel events involved in a single touch interaction.
+// Contact area is modelled as an ellipse with major and minor axis values in normalized device
+// coordinates. If contact area is unknown, report 0.0 for both contact area axis parameters.
+// For circular contact areas or if a minor axis value is not available, pass the same value
+// for major and minor axes. For APIs or devices, that don't report contact area as an ellipse,
+// approximations can be used such as: https://docs.kernel.org/input/multi-touch-protocol.html#event-computation
+//
+// For hover events, the "contact area" is the size of the hovering finger/tool. If unavailable,
+// pass 0.0 for both contact area parameters.
 //
 // If unsupported by the host, this will return LI_ERR_UNSUPPORTED and the caller should consider
 // falling back to other functions to send this input (such as LiSendMousePositionEvent()).
@@ -614,25 +627,26 @@ int LiSendMouseMoveAsMousePositionEvent(short deltaX, short deltaY, short refere
 #define LI_TOUCH_EVENT_CANCEL      0x04
 #define LI_TOUCH_EVENT_BUTTON_ONLY 0x05
 #define LI_TOUCH_EVENT_HOVER_LEAVE 0x06
-int LiSendTouchEvent(uint8_t eventType, uint32_t pointerId, float x, float y, float pressureOrDistance);
+#define LI_ROT_UNKNOWN 0xFFFF
+int LiSendTouchEvent(uint8_t eventType, uint32_t pointerId, float x, float y, float pressureOrDistance,
+                     float contactAreaMajor, float contactAreaMinor, uint16_t rotation);
 
 // This function is similar to LiSendTouchEvent() but allows additional parameters relevant for pen
-// input, including rotation, tilt, and buttons. Rotation is in degrees from vertical in Y dimension
-// (parallel to screen, 0..360) and tilt is in degrees from vertical in Z dimension (perpendicular
-// to screen, 0..90).
+// input, including tilt and buttons. Tilt is in degrees from vertical in Z dimension (perpendicular
+// to screen, 0..90). See LiSendTouchEvent() for detailed documentation on other parameters.
 //
-// x, y, pressure, rotation, and tilt are ignored for LI_TOUCH_EVENT_BUTTON_ONLY events. If one of
-// those changes, send LI_TOUCH_EVENT_MOVE or LI_TOUCH_EVENT_HOVER instead.
+// x, y, pressure, rotation, contact area, and tilt are ignored for LI_TOUCH_EVENT_BUTTON_ONLY events.
+// If one of those changes, send LI_TOUCH_EVENT_MOVE or LI_TOUCH_EVENT_HOVER instead.
 #define LI_TOOL_TYPE_UNKNOWN 0x00
 #define LI_TOOL_TYPE_PEN     0x01
 #define LI_TOOL_TYPE_ERASER  0x02
 #define LI_PEN_BUTTON_PRIMARY   0x01
 #define LI_PEN_BUTTON_SECONDARY 0x02
 #define LI_PEN_BUTTON_TERTIARY  0x04
-#define LI_ROT_UNKNOWN 0xFFFF
 #define LI_TILT_UNKNOWN 0xFF
 int LiSendPenEvent(uint8_t eventType, uint8_t toolType, uint8_t penButtons,
                    float x, float y, float pressureOrDistance,
+                   float contactAreaMajor, float contactAreaMinor,
                    uint16_t rotation, uint8_t tilt);
 
 // This function queues a mouse button event to be sent to the remote server.