diff --git a/html/library_sdl.js b/html/library_sdl.js
index 1c433bf1..7182d275 100644
--- a/html/library_sdl.js
+++ b/html/library_sdl.js
@@ -89,6 +89,7 @@ var LibrarySDL = {
     
     keyCodes: { // DOM code ==> SDL code. See https://developer.mozilla.org/en/Document_Object_Model_%28DOM%29/KeyboardEvent and SDL_keycode.h
       // For keys that don't have unicode value, we map DOM codes with the corresponding scan codes + 1024 (using "| 1 << 10")
+      // See also: https://developer.mozilla.org/en-US/docs/Web/API/KeyboardEvent/keyCode
       16: 225 | 1<<10, // shift
       17: 224 | 1<<10, // control (right, or left)
       18: 226 | 1<<10, // alt
@@ -106,8 +107,8 @@ var LibrarySDL = {
       45: 73 | 1<<10, // insert
       46: 127, // SDLK_DEL == '\177'
       
-      91: 227 | 1<<10, // windows key or super key on linux (doesn't work on Mac)
-      93: 101 | 1<<10, // application
+      91: 227 | 1<<10, // windows key or super key on linux or left command on Mac
+      93: 231 | 1<<10, // application or right command on Mac
       
       96: 98 | 1<<10, // keypad 0
       97: 89 | 1<<10, // keypad 1
@@ -173,7 +174,10 @@ var LibrarySDL = {
       182: 129, // audio volume down
       183: 128, // audio volume up
       
+      186: 59, // semicolon
+      187: 61, // equals
       188: 44, // comma
+      189: 45, // minus
       190: 46, // period
       191: 47, // slash (/)
       192: 96, // backtick/backquote (`)
diff --git a/src/am_backend_emscripten.cpp b/src/am_backend_emscripten.cpp
index 583a122d..ecf8b62f 100644
--- a/src/am_backend_emscripten.cpp
+++ b/src/am_backend_emscripten.cpp
@@ -545,6 +545,8 @@ static am_key convert_key(SDL_Keycode key) {
         case SDLK_RCTRL: return AM_KEY_RCTRL;
         case SDLK_LSHIFT: return AM_KEY_LSHIFT;
         case SDLK_RSHIFT: return AM_KEY_RSHIFT;
+        case SDLK_LGUI: return AM_KEY_LGUI;
+        case SDLK_RGUI: return AM_KEY_RGUI;
         case SDLK_F1: return AM_KEY_F1;
         case SDLK_F2: return AM_KEY_F2;
         case SDLK_F3: return AM_KEY_F3;