diff --git a/src/kaleidoscope/driver/hid/RCMComposite.cpp b/src/kaleidoscope/driver/hid/RCMComposite.cpp
index 22302761..02bf46c8 100644
--- a/src/kaleidoscope/driver/hid/RCMComposite.cpp
+++ b/src/kaleidoscope/driver/hid/RCMComposite.cpp
@@ -26,6 +26,7 @@ USBHID RCMHID;
 HIDKeyboard RCMBootKeyboard(RCMHID, 0);
 HIDKeyboard RCMKeyboard(RCMHID);
 HIDConsumer RCMConsumer(RCMHID);
+HIDMouse RCMMouse(RCMHID);
 USBCompositeSerial CompositeSerial;
 
 } // namespace rcmcomposite
diff --git a/src/kaleidoscope/driver/hid/RCMComposite.h b/src/kaleidoscope/driver/hid/RCMComposite.h
index 2b601d34..20eaaa7b 100644
--- a/src/kaleidoscope/driver/hid/RCMComposite.h
+++ b/src/kaleidoscope/driver/hid/RCMComposite.h
@@ -23,7 +23,7 @@
 #include "kaleidoscope/driver/hid/Base.h"
 
 #include "rcmcomposite/Keyboard.h"
-//#include "rcmcomposite/Mouse.h"
+#include "rcmcomposite/Mouse.h"
 
 namespace kaleidoscope {
 namespace driver {
@@ -38,7 +38,8 @@ extern USBCompositeSerial CompositeSerial;
 const uint8_t report_description_[] = {
   HID_BOOT_KEYBOARD_REPORT_DESCRIPTOR(),
   HID_KEYBOARD_REPORT_DESCRIPTOR(2),
-  HID_CONSUMER_REPORT_DESCRIPTOR(3)
+  HID_CONSUMER_REPORT_DESCRIPTOR(3),
+  HID_MOUSE_REPORT_DESCRIPTOR(4)
 };
 
 }
@@ -46,8 +47,8 @@ const uint8_t report_description_[] = {
 struct RCMCompositeProps: public BaseProps {
   typedef rcmcomposite::KeyboardProps KeyboardProps;
   typedef rcmcomposite::Keyboard<KeyboardProps> Keyboard;
-  //  typedef rcmcomposite::MouseProps MouseProps;
-  //  typedef rcmcomposite::Mouse<MouseProps> Mouse;
+  typedef rcmcomposite::MouseProps MouseProps;
+  typedef rcmcomposite::Mouse<MouseProps> Mouse;
 };
 
 template <typename _Props>
diff --git a/src/kaleidoscope/driver/hid/rcmcomposite/Mouse.h b/src/kaleidoscope/driver/hid/rcmcomposite/Mouse.h
new file mode 100644
index 00000000..35bb1e0b
--- /dev/null
+++ b/src/kaleidoscope/driver/hid/rcmcomposite/Mouse.h
@@ -0,0 +1,81 @@
+// -*- mode: c++ -*-
+/* Kaleidoscope - Firmware for computer input devices
+ * Copyright (C) 2021  Keyboard.io, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License as published by the Free Software
+ * Foundation, version 3.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+#include <Arduino.h>
+#include <USBComposite.h>
+
+#include "kaleidoscope/driver/hid/base/Mouse.h"
+
+namespace kaleidoscope {
+namespace driver {
+namespace hid {
+namespace rcmcomposite {
+
+extern HIDMouse RCMMouse;
+
+/*
+ * We are wrapping `Mouse` here, instead of directly using the class in
+ * `MouseProps` below. We do this, because this lets the linker optimize this
+ * whole thing out if it is unused. It can do that because instantiating `Mouse`
+ * is in a separate compilation unit.
+ *
+ * While it would have been cleaner and shorter to instantiate them here, and
+ * drop the global objects, that prevents optimizing them out, and that's a cost
+ * we do not want to pay.
+ */
+
+class MouseWrapper {
+ public:
+  MouseWrapper() {}
+
+  void begin() {}
+  void sendReport() {
+    RCMMouse.sendReport();
+  }
+  void move(int8_t x, int8_t y, int8_t vWheel, int8_t hWheel) {
+    RCMMouse.move(x, y, vWheel);
+  }
+  void stop(bool x, bool y, bool vWheel = false, bool hWheel = false) {
+    RCMMouse.stop(x, y, vWheel);
+  }
+
+  void releaseAll() {
+    RCMMouse.releaseAll();
+  }
+  void press(uint8_t buttons) {
+    RCMMouse.press(buttons);
+  }
+  void release(uint8_t buttons) {
+    RCMMouse.release(buttons);
+  }
+  void click(uint8_t buttons) {
+    RCMMouse.click(buttons);
+  }
+};
+
+struct MouseProps: public base::MouseProps {
+  typedef MouseWrapper Mouse;
+};
+
+template <typename _Props>
+class Mouse: public base::Mouse<_Props> {};
+
+}
+}
+}
+}