diff --git a/README.md b/README.md
index 7f078eec..328d743f 100644
--- a/README.md
+++ b/README.md
@@ -311,6 +311,7 @@ GLFW.
  * Added `GLFW_VISIBLE` window hint and parameter for controlling and polling
    window visibility
  * Added `GLFW_REPEAT` key action for repeated keys
+ * Added scancode parameter to key callback
  * Added `refreshRate` member to `GLFWvidmode` struct
  * Added key modifier parameter to key and mouse button callbacks
  * Added `windows` simple multi-window test program
diff --git a/examples/boing.c b/examples/boing.c
index 21b3b973..79d2e958 100644
--- a/examples/boing.c
+++ b/examples/boing.c
@@ -43,7 +43,7 @@
 void init( void );
 void display( void );
 void reshape( GLFWwindow* window, int w, int h );
-void key_callback( GLFWwindow* window, int key, int action, int mods );
+void key_callback( GLFWwindow* window, int key, int scancode, int action, int mods );
 void DrawBoingBall( void );
 void BounceBall( double dt );
 void DrawBoingBallBand( GLfloat long_lo, GLfloat long_hi );
@@ -245,7 +245,7 @@ void reshape( GLFWwindow* window, int w, int h )
               0.0, -1.0, 0.0 );         /* up vector */
 }
 
-void key_callback( GLFWwindow* window, int key, int action, int mods )
+void key_callback( GLFWwindow* window, int key, int scancode, int action, int mods )
 {
     if (key == GLFW_KEY_ESCAPE && action == GLFW_PRESS)
         glfwSetWindowShouldClose(window, GL_TRUE);
diff --git a/examples/gears.c b/examples/gears.c
index 6f31aca2..2d445964 100644
--- a/examples/gears.c
+++ b/examples/gears.c
@@ -211,7 +211,7 @@ static void animate(void)
 
 
 /* change view angle, exit upon ESC */
-void key( GLFWwindow* window, int k, int action, int mods )
+void key( GLFWwindow* window, int k, int s, int action, int mods )
 {
   if( action != GLFW_PRESS ) return;
 
diff --git a/examples/heightmap.c b/examples/heightmap.c
index 10907e1d..5ae50bfd 100644
--- a/examples/heightmap.c
+++ b/examples/heightmap.c
@@ -477,7 +477,7 @@ static void update_mesh(void)
  * GLFW callback functions
  *********************************************************************/
 
-static void key_callback(GLFWwindow* window, int key, int action, int mods)
+static void key_callback(GLFWwindow* window, int key, int scancode, int action, int mods)
 {
     switch(key)
     {
diff --git a/examples/splitview.c b/examples/splitview.c
index f20ce206..cb082b7f 100644
--- a/examples/splitview.c
+++ b/examples/splitview.c
@@ -434,7 +434,7 @@ static void mouseButtonFun(GLFWwindow* window, int button, int action, int mods)
     do_redraw = 1;
 }
 
-static void key_callback(GLFWwindow* window, int key, int action, int mods)
+static void key_callback(GLFWwindow* window, int key, int scancode, int action, int mods)
 {
     if (key == GLFW_KEY_ESCAPE && action == GLFW_PRESS)
         glfwSetWindowShouldClose(window, GL_TRUE);
diff --git a/examples/wave.c b/examples/wave.c
index ee7125ef..5237a93f 100644
--- a/examples/wave.c
+++ b/examples/wave.c
@@ -270,7 +270,7 @@ static void error_callback(int error, const char* description)
 // Handle key strokes
 //========================================================================
 
-void key_callback(GLFWwindow* window, int key, int action, int mods)
+void key_callback(GLFWwindow* window, int key, int scancode, int action, int mods)
 {
     if (action != GLFW_PRESS)
         return;
diff --git a/include/GLFW/glfw3.h b/include/GLFW/glfw3.h
index 4ea1b69c..edffe2a4 100644
--- a/include/GLFW/glfw3.h
+++ b/include/GLFW/glfw3.h
@@ -265,6 +265,9 @@ extern "C" {
  *  @{
  */
 
+/* The unknown key */
+#define GLFW_KEY_UNKNOWN            -1
+
 /* Printable keys */
 #define GLFW_KEY_SPACE              32
 #define GLFW_KEY_APOSTROPHE         39  /* ' */
@@ -744,6 +747,7 @@ typedef void (* GLFWscrollfun)(GLFWwindow*,double,double);
  *
  *  @param[in] window The window that received the event.
  *  @param[in] key The [keyboard key](@ref keys) that was pressed or released.
+ *  @param[in] scancode The system-specific scancode of the key.
  *  @param[in] action @ref GLFW_PRESS, @ref GLFW_RELEASE or @ref GLFW_REPEAT.
  *  @param[in] mods Bit field describing which [modifier keys](@ref mods) were
  *  held down.
@@ -752,7 +756,7 @@ typedef void (* GLFWscrollfun)(GLFWwindow*,double,double);
  *
  *  @ingroup input
  */
-typedef void (* GLFWkeyfun)(GLFWwindow*,int,int,int);
+typedef void (* GLFWkeyfun)(GLFWwindow*,int,int,int,int);
 
 /*! @brief The function signature for Unicode character callbacks.
  *
@@ -1771,6 +1775,8 @@ GLFWAPI void glfwSetInputMode(GLFWwindow* window, int mode, int value);
  *  @param[in] key The desired [keyboard key](@ref keys).
  *  @return One of `GLFW_PRESS` or `GLFW_RELEASE`.
  *
+ *  @note `GLFW_KEY_UNKNOWN` is not a valid key for this function.
+ *
  *  @ingroup input
  */
 GLFWAPI int glfwGetKey(GLFWwindow* window, int key);
@@ -1857,6 +1863,14 @@ GLFWAPI void glfwSetCursorPos(GLFWwindow* window, double xpos, double ypos);
  *  focus, i.e. `GLFW_FOCUSED` will be false and the focus callback will have
  *  already been called.
  *
+ *  The scancode of a key is specific to that platform or sometimes even to that
+ *  machine.  Scancodes are intended to allow users to bind keys that don't have
+ *  a GLFW key token.  Such keys have `key` set to `GLFW_KEY_UNKNOWN`, their
+ *  state is not saved and so it cannot be retrieved with @ref glfwGetKey.
+ *
+ *  Sometimes GLFW needs to generate synthetic key events, in which case the
+ *  scancode may be zero.
+ *
  *  @param[in] window The window whose callback to set.
  *  @param[in] cbfun The new key callback, or `NULL` to remove the currently
  *  set callback.
diff --git a/src/cocoa_window.m b/src/cocoa_window.m
index 1d066831..2674db77 100644
--- a/src/cocoa_window.m
+++ b/src/cocoa_window.m
@@ -203,9 +203,9 @@ static void centerCursor(_GLFWwindow *window)
 
 @end
 
-// Converts Mac OS X key modifiers into GLFW ones
+// Translates Mac OS X key modifiers into GLFW ones
 //
-static int convertKeyMods(NSUInteger flags)
+static int translateFlags(NSUInteger flags)
 {
     int mods = 0;
 
@@ -221,9 +221,9 @@ static int convertKeyMods(NSUInteger flags)
     return mods;
 }
 
-// Converts a Mac OS X keycode to a GLFW keycode
+// Translates a Mac OS X keycode to a GLFW keycode
 //
-static int convertMacKeyCode(unsigned int macKeyCode)
+static int translateKey(unsigned int key)
 {
     // Keyboard symbol translation table
     // TODO: Need to find mappings for F13-F15, volume down/up/mute, and eject.
@@ -281,7 +281,7 @@ static int convertMacKeyCode(unsigned int macKeyCode)
         /* 31 */ GLFW_KEY_SPACE,
         /* 32 */ GLFW_KEY_WORLD_1,
         /* 33 */ GLFW_KEY_BACKSPACE,
-        /* 34 */ -1,
+        /* 34 */ GLFW_KEY_UNKNOWN,
         /* 35 */ GLFW_KEY_ESCAPE,
         /* 36 */ GLFW_KEY_RIGHT_SUPER,
         /* 37 */ GLFW_KEY_LEFT_SUPER,
@@ -292,21 +292,21 @@ static int convertMacKeyCode(unsigned int macKeyCode)
         /* 3c */ GLFW_KEY_RIGHT_SHIFT,
         /* 3d */ GLFW_KEY_RIGHT_ALT,
         /* 3e */ GLFW_KEY_RIGHT_CONTROL,
-        /* 3f */ -1, /* Function */
+        /* 3f */ GLFW_KEY_UNKNOWN, /* Function */
         /* 40 */ GLFW_KEY_F17,
         /* 41 */ GLFW_KEY_KP_DECIMAL,
-        /* 42 */ -1,
+        /* 42 */ GLFW_KEY_UNKNOWN,
         /* 43 */ GLFW_KEY_KP_MULTIPLY,
-        /* 44 */ -1,
+        /* 44 */ GLFW_KEY_UNKNOWN,
         /* 45 */ GLFW_KEY_KP_ADD,
-        /* 46 */ -1,
+        /* 46 */ GLFW_KEY_UNKNOWN,
         /* 47 */ GLFW_KEY_NUM_LOCK, /* Really KeypadClear... */
-        /* 48 */ -1, /* VolumeUp */
-        /* 49 */ -1, /* VolumeDown */
-        /* 4a */ -1, /* Mute */
+        /* 48 */ GLFW_KEY_UNKNOWN, /* VolumeUp */
+        /* 49 */ GLFW_KEY_UNKNOWN, /* VolumeDown */
+        /* 4a */ GLFW_KEY_UNKNOWN, /* Mute */
         /* 4b */ GLFW_KEY_KP_DIVIDE,
         /* 4c */ GLFW_KEY_KP_ENTER,
-        /* 4d */ -1,
+        /* 4d */ GLFW_KEY_UNKNOWN,
         /* 4e */ GLFW_KEY_KP_SUBTRACT,
         /* 4f */ GLFW_KEY_F18,
         /* 50 */ GLFW_KEY_F19,
@@ -322,26 +322,26 @@ static int convertMacKeyCode(unsigned int macKeyCode)
         /* 5a */ GLFW_KEY_F20,
         /* 5b */ GLFW_KEY_KP_8,
         /* 5c */ GLFW_KEY_KP_9,
-        /* 5d */ -1,
-        /* 5e */ -1,
-        /* 5f */ -1,
+        /* 5d */ GLFW_KEY_UNKNOWN,
+        /* 5e */ GLFW_KEY_UNKNOWN,
+        /* 5f */ GLFW_KEY_UNKNOWN,
         /* 60 */ GLFW_KEY_F5,
         /* 61 */ GLFW_KEY_F6,
         /* 62 */ GLFW_KEY_F7,
         /* 63 */ GLFW_KEY_F3,
         /* 64 */ GLFW_KEY_F8,
         /* 65 */ GLFW_KEY_F9,
-        /* 66 */ -1,
+        /* 66 */ GLFW_KEY_UNKNOWN,
         /* 67 */ GLFW_KEY_F11,
-        /* 68 */ -1,
+        /* 68 */ GLFW_KEY_UNKNOWN,
         /* 69 */ GLFW_KEY_PRINT_SCREEN,
         /* 6a */ GLFW_KEY_F16,
         /* 6b */ GLFW_KEY_F14,
-        /* 6c */ -1,
+        /* 6c */ GLFW_KEY_UNKNOWN,
         /* 6d */ GLFW_KEY_F10,
-        /* 6e */ -1,
+        /* 6e */ GLFW_KEY_UNKNOWN,
         /* 6f */ GLFW_KEY_F12,
-        /* 70 */ -1,
+        /* 70 */ GLFW_KEY_UNKNOWN,
         /* 71 */ GLFW_KEY_F15,
         /* 72 */ GLFW_KEY_INSERT, /* Really Help... */
         /* 73 */ GLFW_KEY_HOME,
@@ -356,13 +356,13 @@ static int convertMacKeyCode(unsigned int macKeyCode)
         /* 7c */ GLFW_KEY_RIGHT,
         /* 7d */ GLFW_KEY_DOWN,
         /* 7e */ GLFW_KEY_UP,
-        /* 7f */ -1,
+        /* 7f */ GLFW_KEY_UNKNOWN,
     };
 
-    if (macKeyCode >= 128)
-        return -1;
+    if (key >= 128)
+        return GLFW_KEY_UNKNOWN;
 
-    return table[macKeyCode];
+    return table[key];
 }
 
 
@@ -436,7 +436,7 @@ static int convertMacKeyCode(unsigned int macKeyCode)
     _glfwInputMouseClick(window,
                          GLFW_MOUSE_BUTTON_LEFT,
                          GLFW_PRESS,
-                         convertKeyMods([event modifierFlags]));
+                         translateFlags([event modifierFlags]));
 }
 
 - (void)mouseDragged:(NSEvent *)event
@@ -449,7 +449,7 @@ static int convertMacKeyCode(unsigned int macKeyCode)
     _glfwInputMouseClick(window,
                          GLFW_MOUSE_BUTTON_LEFT,
                          GLFW_RELEASE,
-                         convertKeyMods([event modifierFlags]));
+                         translateFlags([event modifierFlags]));
 }
 
 - (void)mouseMoved:(NSEvent *)event
@@ -470,7 +470,7 @@ static int convertMacKeyCode(unsigned int macKeyCode)
     _glfwInputMouseClick(window,
                          GLFW_MOUSE_BUTTON_RIGHT,
                          GLFW_PRESS,
-                         convertKeyMods([event modifierFlags]));
+                         translateFlags([event modifierFlags]));
 }
 
 - (void)rightMouseDragged:(NSEvent *)event
@@ -483,7 +483,7 @@ static int convertMacKeyCode(unsigned int macKeyCode)
     _glfwInputMouseClick(window,
                          GLFW_MOUSE_BUTTON_RIGHT,
                          GLFW_RELEASE,
-                         convertKeyMods([event modifierFlags]));
+                         translateFlags([event modifierFlags]));
 }
 
 - (void)otherMouseDown:(NSEvent *)event
@@ -491,7 +491,7 @@ static int convertMacKeyCode(unsigned int macKeyCode)
     _glfwInputMouseClick(window,
                          [event buttonNumber],
                          GLFW_PRESS,
-                         convertKeyMods([event modifierFlags]));
+                         translateFlags([event modifierFlags]));
 }
 
 - (void)otherMouseDragged:(NSEvent *)event
@@ -504,7 +504,7 @@ static int convertMacKeyCode(unsigned int macKeyCode)
     _glfwInputMouseClick(window,
                          [event buttonNumber],
                          GLFW_RELEASE,
-                         convertKeyMods([event modifierFlags]));
+                         translateFlags([event modifierFlags]));
 }
 
 - (void)mouseExited:(NSEvent *)event
@@ -548,14 +548,11 @@ static int convertMacKeyCode(unsigned int macKeyCode)
 
 - (void)keyDown:(NSEvent *)event
 {
-    const NSUInteger mods = [event modifierFlags];
+    const int key = translateKey([event keyCode]);
+    const int mods = translateFlags([event modifierFlags]);
+    _glfwInputKey(window, key, [event keyCode], GLFW_PRESS, mods);
 
-    _glfwInputKey(window,
-                  convertMacKeyCode([event keyCode]),
-                  GLFW_PRESS,
-                  convertKeyMods(mods));
-
-    if ([event modifierFlags] & NSCommandKeyMask)
+    if (mods & GLFW_MOD_SUPER)
         return;
 
     NSString* characters = [event characters];
@@ -567,7 +564,7 @@ static int convertMacKeyCode(unsigned int macKeyCode)
 
 - (void)flagsChanged:(NSEvent *)event
 {
-    int action, key;
+    int action;
     unsigned int newModifierFlags =
         [event modifierFlags] & NSDeviceIndependentModifierFlagsMask;
 
@@ -578,17 +575,16 @@ static int convertMacKeyCode(unsigned int macKeyCode)
 
     window->ns.modifierFlags = newModifierFlags;
 
-    key = convertMacKeyCode([event keyCode]);
-    if (key != -1)
-        _glfwInputKey(window, key, action, convertKeyMods([event modifierFlags]));
+    const int key = translateKey([event keyCode]);
+    const int mods = translateFlags([event modifierFlags]);
+    _glfwInputKey(window, key, [event keyCode], action, mods);
 }
 
 - (void)keyUp:(NSEvent *)event
 {
-    _glfwInputKey(window,
-                  convertMacKeyCode([event keyCode]),
-                  GLFW_RELEASE,
-                  convertKeyMods([event modifierFlags]));
+    const int key = translateKey([event keyCode]);
+    const int mods = translateFlags([event modifierFlags]);
+    _glfwInputKey(window, key, [event keyCode], GLFW_RELEASE, mods);
 }
 
 - (void)scrollWheel:(NSEvent *)event
diff --git a/src/input.c b/src/input.c
index 9d31a868..c415462e 100644
--- a/src/input.c
+++ b/src/input.c
@@ -122,29 +122,29 @@ static void setStickyMouseButtons(_GLFWwindow* window, int enabled)
 //////                         GLFW event API                       //////
 //////////////////////////////////////////////////////////////////////////
 
-void _glfwInputKey(_GLFWwindow* window, int key, int action, int mods)
+void _glfwInputKey(_GLFWwindow* window, int key, int scancode, int action, int mods)
 {
     GLboolean repeated = GL_FALSE;
 
-    if (key < 0 || key > GLFW_KEY_LAST)
-        return;
-
     if (action == GLFW_RELEASE && window->key[key] == GLFW_RELEASE)
         return;
 
-    if (action == GLFW_PRESS && window->key[key] == GLFW_PRESS)
-        repeated = GL_TRUE;
+    if (key >= 0 && key <= GLFW_KEY_LAST)
+    {
+        if (action == GLFW_PRESS && window->key[key] == GLFW_PRESS)
+            repeated = GL_TRUE;
 
-    if (action == GLFW_RELEASE && window->stickyKeys)
-        window->key[key] = _GLFW_STICK;
-    else
-        window->key[key] = (char) action;
+        if (action == GLFW_RELEASE && window->stickyKeys)
+            window->key[key] = _GLFW_STICK;
+        else
+            window->key[key] = (char) action;
+    }
 
     if (repeated)
         action = GLFW_REPEAT;
 
     if (window->callbacks.key)
-        window->callbacks.key((GLFWwindow*) window, key, action, mods);
+        window->callbacks.key((GLFWwindow*) window, key, scancode, action, mods);
 }
 
 void _glfwInputChar(_GLFWwindow* window, unsigned int character)
diff --git a/src/internal.h b/src/internal.h
index 051b1490..b5655620 100644
--- a/src/internal.h
+++ b/src/internal.h
@@ -606,11 +606,12 @@ void _glfwInputWindowCloseRequest(_GLFWwindow* window);
 /*! @brief Notifies shared code of a physical key event.
  *  @param[in] window The window that received the event.
  *  @param[in] key The key that was pressed or released.
+ *  @param[in] scancode The system-specific scan code of the key.
  *  @param[in] action @ref GLFW_PRESS or @ref GLFW_RELEASE.
  *  @param[in] mods The modifiers pressed when the event was generated.
  *  @ingroup event
  */
-void _glfwInputKey(_GLFWwindow* window, int key, int action, int mods);
+void _glfwInputKey(_GLFWwindow* window, int key, int scancode, int action, int mods);
 
 /*! @brief Notifies shared code of a Unicode character input event.
  *  @param[in] window The window that received the event.
diff --git a/src/win32_window.c b/src/win32_window.c
index 6cff5add..fc7f1209 100644
--- a/src/win32_window.c
+++ b/src/win32_window.c
@@ -34,6 +34,8 @@
 #include <malloc.h>
 #include <windowsx.h>
 
+#define _GLFW_KEY_INVALID -2
+
 
 // Updates the cursor clip rect
 //
@@ -214,7 +216,7 @@ static int translateKey(WPARAM wParam, LPARAM lParam)
                     {
                         // Next message is a RALT down message, which
                         // means that this is not a proper LCTRL message
-                        return -1;
+                        return _GLFW_KEY_INVALID;
                     }
                 }
             }
@@ -360,8 +362,8 @@ static int translateKey(WPARAM wParam, LPARAM lParam)
         default:               break;
     }
 
-    // No matching translation was found, so return -1
-    return -1;
+    // No matching translation was found
+    return GLFW_KEY_UNKNOWN;
 }
 
 // Window callback function (handles window events)
@@ -471,7 +473,12 @@ static LRESULT CALLBACK windowProc(HWND hWnd, UINT uMsg,
         case WM_KEYDOWN:
         case WM_SYSKEYDOWN:
         {
-            _glfwInputKey(window, translateKey(wParam, lParam), GLFW_PRESS, getKeyMods());
+            const int scancode = (lParam >> 16) & 0xff;
+            const int key = translateKey(wParam, lParam);
+            if (key == _GLFW_KEY_INVALID)
+                break;
+
+            _glfwInputKey(window, key, scancode, GLFW_PRESS, getKeyMods());
             break;
         }
 
@@ -500,22 +507,26 @@ static LRESULT CALLBACK windowProc(HWND hWnd, UINT uMsg,
         case WM_SYSKEYUP:
         {
             const int mods = getKeyMods();
+            const int scancode = (lParam >> 16) & 0xff;
+            const int key = translateKey(wParam, lParam);
+            if (key == _GLFW_KEY_INVALID)
+                break;
 
             if (wParam == VK_SHIFT)
             {
                 // Release both Shift keys on Shift up event, as only one event
                 // is sent even if both keys are released
-                _glfwInputKey(window, GLFW_KEY_LEFT_SHIFT, GLFW_RELEASE, mods);
-                _glfwInputKey(window, GLFW_KEY_RIGHT_SHIFT, GLFW_RELEASE, mods);
+                _glfwInputKey(window, GLFW_KEY_LEFT_SHIFT, scancode, GLFW_RELEASE, mods);
+                _glfwInputKey(window, GLFW_KEY_RIGHT_SHIFT, scancode, GLFW_RELEASE, mods);
             }
             else if (wParam == VK_SNAPSHOT)
             {
                 // Key down is not reported for the print screen key
-                _glfwInputKey(window, GLFW_KEY_PRINT_SCREEN, GLFW_PRESS, mods);
-                _glfwInputKey(window, GLFW_KEY_PRINT_SCREEN, GLFW_RELEASE, mods);
+                _glfwInputKey(window, key, scancode, GLFW_PRESS, mods);
+                _glfwInputKey(window, key, scancode, GLFW_RELEASE, mods);
             }
             else
-                _glfwInputKey(window, translateKey(wParam, lParam), GLFW_RELEASE, getKeyMods());
+                _glfwInputKey(window, key, scancode, GLFW_RELEASE, mods);
 
             break;
         }
@@ -1064,10 +1075,10 @@ void _glfwPlatformPollEvents(void)
             // See if this differs from our belief of what has happened
             // (we only have to check for lost key up events)
             if (!lshiftDown && window->key[GLFW_KEY_LEFT_SHIFT] == 1)
-                _glfwInputKey(window, GLFW_KEY_LEFT_SHIFT, GLFW_RELEASE, mods);
+                _glfwInputKey(window, GLFW_KEY_LEFT_SHIFT, 0, GLFW_RELEASE, mods);
 
             if (!rshiftDown && window->key[GLFW_KEY_RIGHT_SHIFT] == 1)
-                _glfwInputKey(window, GLFW_KEY_RIGHT_SHIFT, GLFW_RELEASE, mods);
+                _glfwInputKey(window, GLFW_KEY_RIGHT_SHIFT, 0, GLFW_RELEASE, mods);
         }
 
         // Did the cursor move in an focused window that has captured the cursor
diff --git a/src/window.c b/src/window.c
index fa948adf..26e3dc26 100644
--- a/src/window.c
+++ b/src/window.c
@@ -77,7 +77,7 @@ void _glfwInputWindowFocus(_GLFWwindow* window, GLboolean focused)
             for (i = 0;  i <= GLFW_KEY_LAST;  i++)
             {
                 if (window->key[i] == GLFW_PRESS)
-                    _glfwInputKey(window, i, GLFW_RELEASE, 0);
+                    _glfwInputKey(window, i, 0, GLFW_RELEASE, 0);
             }
 
             // Release all pressed mouse buttons
diff --git a/src/x11_init.c b/src/x11_init.c
index 88b923f9..98973b86 100644
--- a/src/x11_init.c
+++ b/src/x11_init.c
@@ -39,13 +39,13 @@
 
 // Translate an X11 key code to a GLFW key code.
 //
-static int keyCodeToGLFWKeyCode(int keyCode)
+static int translateKey(int keyCode)
 {
     int keySym;
 
     // Valid key code range is  [8,255], according to the XLib manual
     if (keyCode < 8 || keyCode > 255)
-        return -1;
+        return GLFW_KEY_UNKNOWN;
 
     // Try secondary keysym, for numeric keypad keys
     // Note: This way we always force "NumLock = ON", which is intentional
@@ -211,8 +211,8 @@ static int keyCodeToGLFWKeyCode(int keyCode)
         default:                break;
     }
 
-    // No matching translation was found, so return -1
-    return -1;
+    // No matching translation was found
+    return GLFW_KEY_UNKNOWN;
 }
 
 // Update the key code LUT
@@ -225,7 +225,7 @@ static void updateKeyCodeLUT(void)
 
     // Clear the LUT
     for (keyCode = 0;  keyCode < 256;  keyCode++)
-        _glfw.x11.keyCodeLUT[keyCode] = -1;
+        _glfw.x11.keyCodeLUT[keyCode] = GLFW_KEY_UNKNOWN;
 
     // Use XKB to determine physical key locations independently of the current
     // keyboard layout
@@ -296,7 +296,7 @@ static void updateKeyCodeLUT(void)
         else if (strcmp(name, "AB10") == 0) keyCodeGLFW = GLFW_KEY_SLASH;
         else if (strcmp(name, "BKSL") == 0) keyCodeGLFW = GLFW_KEY_BACKSLASH;
         else if (strcmp(name, "LSGT") == 0) keyCodeGLFW = GLFW_KEY_WORLD_1;
-        else keyCodeGLFW = -1;
+        else keyCodeGLFW = GLFW_KEY_UNKNOWN;
 
         // Update the key code LUT
         if ((keyCode >= 0) && (keyCode < 256))
@@ -311,7 +311,7 @@ static void updateKeyCodeLUT(void)
     for (keyCode = 0;  keyCode < 256;  keyCode++)
     {
         if (_glfw.x11.keyCodeLUT[keyCode] < 0)
-            _glfw.x11.keyCodeLUT[keyCode] = keyCodeToGLFWKeyCode(keyCode);
+            _glfw.x11.keyCodeLUT[keyCode] = translateKey(keyCode);
     }
 }
 
diff --git a/src/x11_window.c b/src/x11_window.c
index c83cae75..7c118dd2 100644
--- a/src/x11_window.c
+++ b/src/x11_window.c
@@ -83,8 +83,8 @@ static int translateKey(int keycode)
     // Use the pre-filled LUT (see updateKeyCodeLUT() in x11_init.c)
     if ((keycode >= 0) && (keycode < 256))
         return _glfw.x11.keyCodeLUT[keycode];
-    else
-        return -1;
+
+    return GLFW_KEY_UNKNOWN;
 }
 
 // Translates an X Window event to Unicode
@@ -515,7 +515,7 @@ static void processEvent(XEvent *event)
             const int key = translateKey(event->xkey.keycode);
             const int mods = translateState(event->xkey.state);
 
-            _glfwInputKey(window, key, GLFW_PRESS, mods);
+            _glfwInputKey(window, key, event->xkey.keycode, GLFW_PRESS, mods);
 
             if (!(mods & GLFW_MOD_CONTROL) && !(mods & GLFW_MOD_ALT))
                 _glfwInputChar(window, translateChar(&event->xkey));
@@ -528,7 +528,7 @@ static void processEvent(XEvent *event)
             const int key = translateKey(event->xkey.keycode);
             const int mods = translateState(event->xkey.state);
 
-            _glfwInputKey(window, key, GLFW_RELEASE, mods);
+            _glfwInputKey(window, key, event->xkey.keycode, GLFW_RELEASE, mods);
             break;
         }
 
diff --git a/tests/accuracy.c b/tests/accuracy.c
index 752c6951..a94e9188 100644
--- a/tests/accuracy.c
+++ b/tests/accuracy.c
@@ -74,7 +74,7 @@ static void cursor_position_callback(GLFWwindow* window, double x, double y)
     cursor_y = y;
 }
 
-static void key_callback(GLFWwindow* window, int key, int action, int mods)
+static void key_callback(GLFWwindow* window, int key, int scancode, int action, int mods)
 {
     if (key == GLFW_KEY_SPACE && action == GLFW_PRESS)
         set_swap_interval(window, 1 - swap_interval);
diff --git a/tests/clipboard.c b/tests/clipboard.c
index 8efd63fe..43422845 100644
--- a/tests/clipboard.c
+++ b/tests/clipboard.c
@@ -44,7 +44,7 @@ static void error_callback(int error, const char* description)
     fprintf(stderr, "Error: %s\n", description);
 }
 
-static void key_callback(GLFWwindow* window, int key, int action, int mods)
+static void key_callback(GLFWwindow* window, int key, int scancode, int action, int mods)
 {
     if (action != GLFW_PRESS)
         return;
diff --git a/tests/events.c b/tests/events.c
index a4e3476a..320af621 100644
--- a/tests/events.c
+++ b/tests/events.c
@@ -172,6 +172,7 @@ static const char* get_key_name(int key)
         case GLFW_KEY_LEFT_SUPER:   return "LEFT SUPER";
         case GLFW_KEY_RIGHT_SUPER:  return "RIGHT SUPER";
         case GLFW_KEY_MENU:         return "MENU";
+        case GLFW_KEY_UNKNOWN:      return "UNKNOWN";
 
         default:                    return NULL;
     }
@@ -339,11 +340,12 @@ static void scroll_callback(GLFWwindow* window, double x, double y)
     printf("%08x at %0.3f: Scroll: %0.3f %0.3f\n", counter++, glfwGetTime(), x, y);
 }
 
-static void key_callback(GLFWwindow* window, int key, int action, int mods)
+static void key_callback(GLFWwindow* window, int key, int scancode, int action, int mods)
 {
     const char* name = get_key_name(key);
 
-    printf("%08x at %0.3f: Key 0x%04x", counter++, glfwGetTime(), key);
+    printf("%08x at %0.3f: Key 0x%04x Scancode 0x%04x",
+           counter++, glfwGetTime(), key, scancode);
 
     if (name)
         printf(" (%s)", name);
diff --git a/tests/fsaa.c b/tests/fsaa.c
index 952264bb..1725825c 100644
--- a/tests/fsaa.c
+++ b/tests/fsaa.c
@@ -48,7 +48,7 @@ static void framebuffer_size_callback(GLFWwindow* window, int width, int height)
     glViewport(0, 0, width, height);
 }
 
-static void key_callback(GLFWwindow* window, int key, int action, int mods)
+static void key_callback(GLFWwindow* window, int key, int scancode, int action, int mods)
 {
     if (action != GLFW_PRESS)
         return;
diff --git a/tests/gamma.c b/tests/gamma.c
index 136782db..19dc35df 100644
--- a/tests/gamma.c
+++ b/tests/gamma.c
@@ -60,7 +60,7 @@ static void error_callback(int error, const char* description)
     fprintf(stderr, "Error: %s\n", description);
 }
 
-static void key_callback(GLFWwindow* window, int key, int action, int mods)
+static void key_callback(GLFWwindow* window, int key, int scancode, int action, int mods)
 {
     if (action != GLFW_PRESS)
         return;
diff --git a/tests/iconify.c b/tests/iconify.c
index dc9b799c..361fe2f5 100644
--- a/tests/iconify.c
+++ b/tests/iconify.c
@@ -45,7 +45,7 @@ static void error_callback(int error, const char* description)
     fprintf(stderr, "Error: %s\n", description);
 }
 
-static void key_callback(GLFWwindow* window, int key, int action, int mods)
+static void key_callback(GLFWwindow* window, int key, int scancode, int action, int mods)
 {
     printf("%0.2f Key %s\n",
            glfwGetTime(),
diff --git a/tests/modes.c b/tests/modes.c
index e92a262c..37e9a675 100644
--- a/tests/modes.c
+++ b/tests/modes.c
@@ -74,7 +74,7 @@ static void framebuffer_size_callback(GLFWwindow* window, int width, int height)
     glViewport(0, 0, width, height);
 }
 
-static void key_callback(GLFWwindow* window, int key, int action, int mods)
+static void key_callback(GLFWwindow* window, int key, int scancode, int action, int mods)
 {
     if (key == GLFW_KEY_ESCAPE)
         glfwSetWindowShouldClose(window, GL_TRUE);
diff --git a/tests/peter.c b/tests/peter.c
index 51672831..030ea509 100644
--- a/tests/peter.c
+++ b/tests/peter.c
@@ -65,7 +65,7 @@ static void cursor_position_callback(GLFWwindow* window, double x, double y)
     cursor_y = y;
 }
 
-static void key_callback(GLFWwindow* window, int key, int action, int mods)
+static void key_callback(GLFWwindow* window, int key, int scancode, int action, int mods)
 {
     switch (key)
     {
diff --git a/tests/reopen.c b/tests/reopen.c
index 40f9ef75..edcbd717 100644
--- a/tests/reopen.c
+++ b/tests/reopen.c
@@ -54,7 +54,7 @@ static void window_close_callback(GLFWwindow* window)
     printf("Close callback triggered\n");
 }
 
-static void key_callback(GLFWwindow* window, int key, int action, int mods)
+static void key_callback(GLFWwindow* window, int key, int scancode, int action, int mods)
 {
     if (action != GLFW_PRESS)
         return;
diff --git a/tests/sharing.c b/tests/sharing.c
index 6a951c88..030ea110 100644
--- a/tests/sharing.c
+++ b/tests/sharing.c
@@ -44,7 +44,7 @@ static void error_callback(int error, const char* description)
     fprintf(stderr, "Error: %s\n", description);
 }
 
-static void key_callback(GLFWwindow* window, int key, int action, int mods)
+static void key_callback(GLFWwindow* window, int key, int scancode, int action, int mods)
 {
     if (action == GLFW_PRESS && key == GLFW_KEY_ESCAPE)
         glfwSetWindowShouldClose(window, GL_TRUE);
diff --git a/tests/tearing.c b/tests/tearing.c
index 58135ce8..94865fab 100644
--- a/tests/tearing.c
+++ b/tests/tearing.c
@@ -64,7 +64,7 @@ static void framebuffer_size_callback(GLFWwindow* window, int width, int height)
     glViewport(0, 0, width, height);
 }
 
-static void key_callback(GLFWwindow* window, int key, int action, int mods)
+static void key_callback(GLFWwindow* window, int key, int scancode, int action, int mods)
 {
     if (key == GLFW_KEY_SPACE && action == GLFW_PRESS)
         set_swap_interval(window, 1 - swap_interval);