diff --git a/common/src/misc/tldjs.noop.ts b/common/src/misc/tldjs.noop.ts
index 74a02918fb..b3bd6db774 100644
--- a/common/src/misc/tldjs.noop.ts
+++ b/common/src/misc/tldjs.noop.ts
@@ -1,3 +1,7 @@
 export function getDomain(host: string): string | null {
     return null;
 }
+
+export function isValid(host: string): boolean {
+    return true;
+}
diff --git a/common/src/misc/utils.ts b/common/src/misc/utils.ts
index 5e87d1e7c2..375a58c92e 100644
--- a/common/src/misc/utils.ts
+++ b/common/src/misc/utils.ts
@@ -221,6 +221,11 @@ export class Utils {
         if (httpUrl) {
             try {
                 const url = Utils.getUrlObject(uriString);
+                const validHostname = tldjs?.isValid != null ? tldjs.isValid(url.hostname) : true;
+                if (!validHostname) {
+                    return null;
+                }
+
                 if (url.hostname === 'localhost' || Utils.validIpAddress(url.hostname)) {
                     return url.hostname;
                 }
diff --git a/spec/common/misc/utils.spec.ts b/spec/common/misc/utils.spec.ts
index 4c473c14c8..97c3d1e562 100644
--- a/spec/common/misc/utils.spec.ts
+++ b/spec/common/misc/utils.spec.ts
@@ -33,6 +33,11 @@ describe('Utils Service', () => {
             expect(Utils.getDomain('https://localhost')).toBe('localhost');
             expect(Utils.getDomain('https://192.168.1.1')).toBe('192.168.1.1');
         });
+
+        it('should reject invalid hostnames', () => {
+            expect(Utils.getDomain('https://mywebsite.com$.mywebsite.com')).toBeNull();
+            expect(Utils.getDomain('https://mywebsite.com!.mywebsite.com')).toBeNull();
+        });
     });
 
     describe('getHostname', () => {