diff --git a/src/login/i18n/noJsx/getI18n.tsx b/src/login/i18n/noJsx/getI18n.tsx
index 56fded1c..2c310776 100644
--- a/src/login/i18n/noJsx/getI18n.tsx
+++ b/src/login/i18n/noJsx/getI18n.tsx
@@ -1,5 +1,6 @@
 import "keycloakify/tools/Object.fromEntries";
 import { assert, is } from "tsafe/assert";
+import { extractLastParenthesisContent } from "keycloakify/tools/extractLastParenthesisContent";
 import messages_defaultSet_fallbackLanguage from "../messages_defaultSet/en";
 import { fetchMessages_defaultSet } from "../messages_defaultSet";
 import type { KcContext } from "../../KcContext";
@@ -168,12 +169,10 @@ export function createGetI18n<
                     break from_server;
                 }
 
-                // cspell: disable-next-line
-                // from "Espagnol (Español)" we want to extract "Español"
-                const match = supportedEntry.label.match(/[^(]+\(([^)]+)\)/);
+                const lastParenthesisContent = extractLastParenthesisContent(supportedEntry.label);
 
-                if (match !== null) {
-                    return match[1];
+                if (lastParenthesisContent !== undefined) {
+                    return lastParenthesisContent;
                 }
 
                 return supportedEntry.label;
diff --git a/src/tools/extractLastParenthesisContent.ts b/src/tools/extractLastParenthesisContent.ts
new file mode 100644
index 00000000..42643dbc
--- /dev/null
+++ b/src/tools/extractLastParenthesisContent.ts
@@ -0,0 +1,43 @@
+/**
+ * "Hello (world)" => "world"
+ * "Hello (world) (foo)" => "foo"
+ * "Hello (world (foo))" => "world (foo)"
+ */
+export function extractLastParenthesisContent(str: string): string | undefined {
+    const chars: string[] = [];
+
+    for (const char of str) {
+        chars.push(char);
+    }
+
+    const extractedChars: string[] = [];
+    let openingCount = 0;
+
+    loop_through_char: for (let i = chars.length - 1; i >= 0; i--) {
+        const char = chars[i];
+
+        if (i === chars.length - 1) {
+            if (char !== ")") {
+                return undefined;
+            }
+
+            continue;
+        }
+
+        switch (char) {
+            case ")":
+                openingCount++;
+                break;
+            case "(":
+                if (openingCount === 0) {
+                    return extractedChars.join("");
+                }
+                openingCount--;
+                break;
+        }
+
+        extractedChars.unshift(char);
+    }
+
+    return undefined;
+}