diff --git a/app/assets/javascripts/discourse-common/addon/lib/get-url.js b/app/assets/javascripts/discourse-common/addon/lib/get-url.js
index 1981a38bfbe..29a9e56ce14 100644
--- a/app/assets/javascripts/discourse-common/addon/lib/get-url.js
+++ b/app/assets/javascripts/discourse-common/addon/lib/get-url.js
@@ -15,9 +15,9 @@ export default function getURL(url) {
     return url;
   }
 
-  const found = url.indexOf(baseUri);
+  const found = url.startsWith(baseUri);
 
-  if (found >= 0 && found < 3) {
+  if (found) {
     return url;
   }
   if (url[0] !== "/") {
diff --git a/app/assets/javascripts/discourse/tests/unit/lib/get-url-test.js b/app/assets/javascripts/discourse/tests/unit/lib/get-url-test.js
index 82d86b838a9..626de266790 100644
--- a/app/assets/javascripts/discourse/tests/unit/lib/get-url-test.js
+++ b/app/assets/javascripts/discourse/tests/unit/lib/get-url-test.js
@@ -60,6 +60,12 @@ module("Unit | Utility | get-url", function () {
       "relative url has subfolder"
     );
 
+    assert.equal(
+      getURL("/u/forumadmin"),
+      "/forum/u/forumadmin",
+      "relative url has subfolder even if username contains subfolder"
+    );
+
     assert.equal(
       getURL(""),
       "/forum",