diff --git a/external/Optional/optional.hpp b/external/Optional/optional.hpp
index 82c995acc..9b0f4b833 100644
--- a/external/Optional/optional.hpp
+++ b/external/Optional/optional.hpp
@@ -190,6 +190,8 @@ template <class T> inline constexpr typename std::remove_reference<T>::type&& co
   {
   # if defined(EMSCRIPTEN) && EMSCRIPTEN
     __assert_fail(expr, file, line, "");
+  # elif defined __native_client__
+    __assert(expr, line, file); // WHY.
   # elif defined __clang__ || defined __GNU_LIBRARY__
     __assert(expr, file, line);
   # elif defined __GNUC__
diff --git a/src/Platform/NaClApplication.cpp b/src/Platform/NaClApplication.cpp
index 15ac0c1c3..6a8c28b4c 100644
--- a/src/Platform/NaClApplication.cpp
+++ b/src/Platform/NaClApplication.cpp
@@ -34,6 +34,13 @@
 
 namespace Magnum { namespace Platform {
 
+static_assert(NaClApplication::MouseEvent::Button::WheelUp != NaClApplication::MouseEvent::Button::Left &&
+              NaClApplication::MouseEvent::Button::WheelUp != NaClApplication::MouseEvent::Button::Middle &&
+              NaClApplication::MouseEvent::Button::WheelUp != NaClApplication::MouseEvent::Button::Right &&
+              NaClApplication::MouseEvent::Button::WheelDown != NaClApplication::MouseEvent::Button::Left &&
+              NaClApplication::MouseEvent::Button::WheelDown != NaClApplication::MouseEvent::Button::Middle &&
+              NaClApplication::MouseEvent::Button::WheelDown != NaClApplication::MouseEvent::Button::Right, "");
+
 struct NaClApplication::ConsoleDebugOutput {
     explicit ConsoleDebugOutput(pp::Instance* instance);
 
@@ -201,6 +208,15 @@ bool NaClApplication::HandleInputEvent(const pp::InputEvent& event) {
             break;
         }
 
+        case PP_INPUTEVENT_TYPE_WHEEL: {
+            pp::WheelInputEvent wheelEvent(event);
+            if(Math::TypeTraits<Float>::equals(wheelEvent.GetDelta().y(), 0.0f)) return false;
+            MouseEvent e(wheelEvent.GetDelta().y() > 0 ? MouseEvent::Button::WheelUp : MouseEvent::Button::WheelDown, {}, static_cast<InputEvent::Modifier>(wheelEvent.GetModifiers()));
+            mousePressEvent(e);
+            if(!e.isAccepted()) return false;
+            break;
+        }
+
         case PP_INPUTEVENT_TYPE_MOUSEMOVE: {
             pp::MouseInputEvent mouseEvent(event);
             MouseMoveEvent e({mouseEvent.GetPosition().x(), mouseEvent.GetPosition().y()},  {mouseEvent.GetMovement().x(), mouseEvent.GetMovement().y()}, static_cast<InputEvent::Modifier>(mouseEvent.GetModifiers()));
diff --git a/src/Platform/NaClApplication.h b/src/Platform/NaClApplication.h
index c629ac9d6..394debc62 100644
--- a/src/Platform/NaClApplication.h
+++ b/src/Platform/NaClApplication.h
@@ -624,13 +624,21 @@ class NaClApplication::MouseEvent: public NaClApplication::InputEvent {
         enum class Button: unsigned int {
             Left = PP_INPUTEVENT_MOUSEBUTTON_LEFT,      /**< Left button */
             Middle = PP_INPUTEVENT_MOUSEBUTTON_MIDDLE,  /**< Middle button */
-            Right = PP_INPUTEVENT_MOUSEBUTTON_RIGHT     /**< Right button */
+            Right = PP_INPUTEVENT_MOUSEBUTTON_RIGHT,    /**< Right button */
+            WheelUp = 0xFFFF01,                         /**< Wheel up */
+            WheelDown = 0xFFFF02                        /**< Wheel down */
         };
 
         /** @brief Button */
         constexpr Button button() const { return _button; }
 
-        /** @brief Position */
+        /**
+         * @brief Position
+         *
+         * @attention Note that due to the way the @ref Button::WheelUp and
+         *      @ref Button::WheelDown events are handled by Native Client, the
+         *      position information is not available, i.e. it is set to zero.
+         */
         constexpr Vector2i position() const { return _position; }
 
     private: