diff --git a/README.md b/README.md
index 9b0e68e..259cfa4 100644
--- a/README.md
+++ b/README.md
@@ -108,10 +108,10 @@ for (const el of document.querySelectorAll('[data-shortcut]')) {
 6. `"Mod"` is a special modifier that localizes to `Meta` on MacOS/iOS, and `Control` on Windows/Linux.
    1. `"Mod+"` can appear in any order in a hotkey string. For example: `"Mod+Alt+Shift+KEY"`
    2. Neither the `Control` or `Meta` modifiers should appear in a hotkey string with `Mod`.
-   3. Due to the inconsistent lowercasing of `event.key` on Mac and iOS when `Meta` is pressed along with `Shift`, it is recommended to avoid hotkey strings containing both `Mod` and `Shift`.
 7. `"Plus"` and `"Space"` are special key names to represent the `+` and ` ` keys respectively, because these symbols cannot be represented in the normal hotkey string syntax.
 8. You can use the comma key `,` as a hotkey, e.g. `a,,` would activate if the user typed `a` or `,`. `Control+,,x` would activate for `Control+,` or `x`.
-9. `"Shift"` should be included if it would be held and the key is uppercase: ie, `Shift+A` not `A`. Note however that MacOS outputs lowercase keys when `Meta+Shift` is held (ie, `Meta+Shift+a`); see 6.3 above.
+9. `"Shift"` should be included if it would be held and the key is uppercase: ie, `Shift+A` not `A`
+   1. MacOS outputs lowercase key names when `Meta+Shift` is held (ie, `Meta+Shift+a`). In an attempt to normalize this, `hotkey` will automatically map these key names to uppercase, so the uppercase keys should still be used (ie, `"Meta+Shift+A"` or `"Mod+Shift+A"`). **However**, this normalization only works on US keyboard layouts.
 
 ### Example
 
@@ -119,7 +119,6 @@ The following hotkey would match if the user typed the key sequence `a` and then
 
 ```js
 'a b,Control+Alt+/'
-
 ```
 
 🔬 **Hotkey Mapper** is a tool to help you determine the correct hotkey string for your key combination: <https://github.github.io/hotkey/pages/hotkey_mapper.html>
diff --git a/src/hotkey.ts b/src/hotkey.ts
index 4840fcf..551c718 100644
--- a/src/hotkey.ts
+++ b/src/hotkey.ts
@@ -1,5 +1,6 @@
 import {NormalizedSequenceString} from './sequence.js'
 import {macosSymbolLayerKeys} from './macos-symbol-layer.js'
+import {macosUppercaseLayerKeys} from './macos-uppercase-layer.js'
 
 const normalizedHotkeyBrand = Symbol('normalizedHotkey')
 
@@ -47,9 +48,19 @@ export function eventToHotkeyString(
   }
 
   if (!modifierKeyNames.includes(key)) {
-    const nonOptionPlaneKey =
+    // MacOS outputs symbols when `Alt` is held, so we map them back to the key symbol if we can
+    const altNormalizedKey =
       hotkeyString.includes('Alt') && matchApplePlatform.test(platform) ? macosSymbolLayerKeys[key] ?? key : key
-    const syntheticKey = syntheticKeyNames[nonOptionPlaneKey] ?? nonOptionPlaneKey
+
+    // MacOS outputs lowercase characters when `Command+Shift` is held, so we map them back to uppercase if we can
+    const shiftNormalizedKey =
+      hotkeyString.includes('Shift') && matchApplePlatform.test(platform)
+        ? macosUppercaseLayerKeys[altNormalizedKey] ?? altNormalizedKey
+        : altNormalizedKey
+
+    // Some symbols can't be used because of hotkey string format, so we replace them with 'synthetic' named keys
+    const syntheticKey = syntheticKeyNames[shiftNormalizedKey] ?? shiftNormalizedKey
+
     hotkeyString.push(syntheticKey)
   }
 
@@ -84,12 +95,12 @@ function localizeMod(hotkey: string, platform: string = navigator.platform): str
 
 function sortModifiers(hotkey: string): string {
   const key = hotkey.split('+').pop()
-  const modifiers = []
+  const modifiers: string[] = []
   for (const modifier of ['Control', 'Alt', 'Meta', 'Shift']) {
     if (hotkey.includes(modifier)) {
       modifiers.push(modifier)
     }
   }
-  modifiers.push(key)
+  if (key) modifiers.push(key)
   return modifiers.join('+')
 }
diff --git a/src/macos-uppercase-layer.ts b/src/macos-uppercase-layer.ts
new file mode 100644
index 0000000..4b835af
--- /dev/null
+++ b/src/macos-uppercase-layer.ts
@@ -0,0 +1,55 @@
+/**
+ * Map of 'uppercase' symbols to the keys that would be pressed (while holding `Shift`) to type them on MacOS on an
+ * English layout. Most of these are standardized across most language layouts, so this won't work 100% in every
+ * language but it should work most of the time.
+ *
+ */
+export const macosUppercaseLayerKeys: Record<string, string> = {
+  ['`']: '~',
+  ['1']: '!',
+  ['2']: '@',
+  ['3']: '#',
+  ['4']: '$',
+  ['5']: '%',
+  ['6']: '^',
+  ['7']: '&',
+  ['8']: '*',
+  ['9']: '(',
+  ['0']: ')',
+  ['-']: '_',
+  ['=']: '+',
+  ['[']: '{',
+  [']']: '}',
+  ['\\']: '|',
+  [';']: ':',
+  ["'"]: '"',
+  [',']: '<',
+  ['.']: '>',
+  ['/']: '?',
+  ['q']: 'Q',
+  ['w']: 'W',
+  ['e']: 'E',
+  ['r']: 'R',
+  ['t']: 'T',
+  ['y']: 'Y',
+  ['u']: 'U',
+  ['i']: 'I',
+  ['o']: 'O',
+  ['p']: 'P',
+  ['a']: 'A',
+  ['s']: 'S',
+  ['d']: 'D',
+  ['f']: 'F',
+  ['g']: 'G',
+  ['h']: 'H',
+  ['j']: 'J',
+  ['k']: 'K',
+  ['l']: 'L',
+  ['z']: 'Z',
+  ['x']: 'X',
+  ['c']: 'C',
+  ['v']: 'V',
+  ['b']: 'B',
+  ['n']: 'N',
+  ['m']: 'M'
+}
diff --git a/test/test.js b/test/test.js
index 17b33cd..5119ded 100644
--- a/test/test.js
+++ b/test/test.js
@@ -286,7 +286,11 @@ describe('hotkey', function () {
       ['Alt+Shift+ArrowLeft', {altKey: true, shiftKey: true, key: 'ArrowLeft'}],
       ['Alt+Shift+ArrowLeft', {altKey: true, shiftKey: true, key: 'ArrowLeft'}, 'mac'],
       ['Control+Space', {ctrlKey: true, key: ' '}],
-      ['Shift+Plus', {shiftKey: true, key: '+'}]
+      ['Shift+Plus', {shiftKey: true, key: '+'}],
+      ['Meta+Shift+X', {metaKey: true, shiftKey: true, key: 'x'}, 'mac'],
+      ['Control+Shift+X', {ctrlKey: true, shiftKey: true, key: 'X'}],
+      ['Meta+Shift+!', {metaKey: true, shiftKey: true, key: '1'}, 'mac'],
+      ['Control+Shift+!', {ctrlKey: true, shiftKey: true, key: '!'}]
     ]
     for (const [expected, keyEvent, platform = 'win / linux'] of tests) {
       it(`${JSON.stringify(keyEvent)} => ${expected}`, function (done) {