diff --git a/freesound/static/bw-frontend/src/components/uiThemeDetector.js b/freesound/static/bw-frontend/src/components/uiThemeDetector.js
index 08e2ea8bc..606c443f7 100644
--- a/freesound/static/bw-frontend/src/components/uiThemeDetector.js
+++ b/freesound/static/bw-frontend/src/components/uiThemeDetector.js
@@ -20,17 +20,18 @@ const isUsingDarkTheme = () => {
     return styleLink.getAttribute('href').indexOf('dark') > -1;
 }
 
-window.matchMedia('(prefers-color-scheme: dark)').addEventListener('change', event => {
-    const newColorScheme = event.matches ? "dark" : "light";
-    if (styleLink.dataset.forcedTheme === undefined){
-        if (newColorScheme == "dark"){
-            switchToDarkMode();
-        } else if (newColorScheme == "dark"){
-            switchToLightMode();
+if (window.matchMedia('(prefers-color-scheme: dark)').addEventListener !== undefined){  // Some old browsers don't support that
+    window.matchMedia('(prefers-color-scheme: dark)').addEventListener('change', event => {
+        const newColorScheme = event.matches ? "dark" : "light";
+        if (styleLink.dataset.forcedTheme === undefined){
+            if (newColorScheme == "dark"){
+                switchToDarkMode();
+            } else if (newColorScheme == "dark"){
+                switchToLightMode();
+            }
         }
-    }
-});
-
+    });
+}
 
 if (browserPrefersDarkTheme()){
     document.cookie = "systemPrefersDarkTheme=yes;path=/";
diff --git a/freesound/static/bw-frontend/src/index.js b/freesound/static/bw-frontend/src/index.js
index aecf93ae6..a546a7353 100644
--- a/freesound/static/bw-frontend/src/index.js
+++ b/freesound/static/bw-frontend/src/index.js
@@ -9,3 +9,4 @@ import 'normalize.css'
 import '../styles/index.scss'
 
 import './components'
+import './utils/polyfills'
\ No newline at end of file
diff --git a/freesound/static/bw-frontend/src/utils/polyfills.js b/freesound/static/bw-frontend/src/utils/polyfills.js
new file mode 100644
index 000000000..694500eaf
--- /dev/null
+++ b/freesound/static/bw-frontend/src/utils/polyfills.js
@@ -0,0 +1,10 @@
+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);
+	};
+}
\ No newline at end of file