diff --git a/README.md b/README.md
index dea2913..3aeb84b 100644
--- a/README.md
+++ b/README.md
@@ -18,7 +18,7 @@ Android port of OMORI RPG game
 
 - [ ] Options menu fix
 - [x] Physical gamepad support
-- [ ] replaceAll polyfill
+- [x] replaceAll polyfill
 - [ ] External saves (Android/data)
 - [ ] Cordova localhost bug
 - [x] WakeLock
diff --git a/www/js/porting/compat/nwjs.js b/www/js/porting/compat/nwjs.js
index d5851cc..ef761bd 100644
--- a/www/js/porting/compat/nwjs.js
+++ b/www/js/porting/compat/nwjs.js
@@ -2,6 +2,26 @@
 
 window._MEMO_PATHS = {}
 
+/**
+ * String.prototype.replaceAll() polyfill
+ * https://gomakethings.com/how-to-replace-a-section-of-a-string-with-another-one-with-vanilla-js/
+ * @author Chris Ferdinandi
+ * @license MIT
+ */
+if (!String.prototype.replaceAll) {
+	String.prototype.replaceAll = function(str, newStr){
+
+		// If a regex pattern
+		if (Object.prototype.toString.call(str).toLowerCase() === '[object regexp]') {
+			return this.replace(str, newStr);
+		}
+
+		// If a string
+		return this.replace(new RegExp(str, 'g'), newStr);
+
+	};
+}
+
 function replaceSpecialSymbols(s) {
     const memoized = _MEMO_PATHS[s];
     if (memoized != undefined) {