diff --git a/src/App.php b/src/App.php
index 4177c336d1..c6a251110f 100644
--- a/src/App.php
+++ b/src/App.php
@@ -673,11 +673,9 @@ public function url($page = [], array $extraRequestUrlArgs = []): string
             if ($pagePath === '') { // TODO path must always start with '/'
                 $pagePath = '/';
             }
-            if (str_ends_with($pagePath, '/')) {
-                $pagePath = $this->urlBuildingIndexPage;
-            } else {
-                $pagePath = basename($pagePath, $this->urlBuildingExt);
-            }
+        }
+        if (str_ends_with($pagePath, '/')) {
+            $pagePath .= $this->urlBuildingIndexPage;
         }
         if (!str_ends_with($pagePath, '/') && !str_contains(basename($pagePath), '.')) {
             $pagePath .= $this->urlBuildingExt;
diff --git a/tests/AppTest.php b/tests/AppTest.php
index 56b1bd2410..900b0d5f3e 100644
--- a/tests/AppTest.php
+++ b/tests/AppTest.php
@@ -82,6 +82,12 @@ public function provideUrlCases(): iterable
             yield [$requestPage . '?u=U', [], ['x'], [], 'x.php'];
             yield [$requestPage . '?index.php', [], ['x'], [], 'x.php'];
 
+            // /w page autoindex
+            yield [$requestPage, [], ['/'], [], '/index.php'];
+            yield [$requestPage, [], ['/0/0/'], [], '/0/0/index.php'];
+            yield [$requestPage, [], ['a.b c/'], [], 'a.b c/index.php'];
+            yield [$requestPage . '?u=U', [], ['x/'], [], 'x/index.php'];
+
             // /w page args
             yield [$requestPage, [], ['x', 'foo' => 'a'], [], 'x.php?foo=a'];
             yield [$requestPage, [], ['x', 'foo' => 'a', 'bar' => '0'], [], 'x.php?foo=a&bar=0'];
@@ -106,6 +112,11 @@ public function provideUrlCases(): iterable
         yield ['/', ['v' => false], ['x', 'v' => 'page'], [], 'x.php?v=page'];
         yield ['/', ['v' => false], ['x'], ['v' => 'extra'], 'x.php'];
 
+        // /wo page path
+        yield ['/x', [], [], [], '/x.php'];
+        yield ['/d/x.html', [], ['foo' => 'a'], [], '/d/x.html?foo=a'];
+        yield ['/?u=U&v=V', ['v' => true], [], [], '/index.php?v=V'];
+
         // args priority
         yield ['/', [], ['x', 'foo' => 'page'], ['foo' => 'extra'], 'x.php?foo=page'];
         yield ['/?foo=sticky', ['foo' => true], ['x', 'foo' => 'page'], ['foo' => 'extra'], 'x.php?foo=page'];
@@ -133,23 +144,35 @@ public function testUrl(string $requestUrl, array $appStickyGetArguments, array
         self::assertSame($expectedUrl, $app->url(($page[0] ?? '') . (count($pageAssocOnly) > 0 ? '?' . implode('&', array_map(static fn ($k) => $k . '=' . $pageAssocOnly[$k], array_keys($pageAssocOnly))) : ''), $extraRequestUrlArgs));
         self::assertSame($expectedUrl, $app->jsUrl($page, array_merge(['__atk_json' => null], $extraRequestUrlArgs)));
 
-        $makeExpectedUrlFx = static function (string $ext) use ($page, $expectedUrl) {
-            return preg_replace_callback('~^[^?]*?\K(\.php)(?=\?|$)~', static function ($matches) use ($page, $ext) {
-                if ($matches[1] !== '' && !preg_match('~\.php(?=\?|$)~', $page[0] ?? '')) {
-                    $matches[1] = $ext;
+        $makeExpectedUrlFx = static function (string $indexPage, string $ext) use ($page, $expectedUrl) {
+            return preg_replace_callback('~^[^?]*?\K([^/?]*)(\.php)(?=\?|$)~', static function ($matches) use ($page, $indexPage, $ext) {
+                if ($matches[1] === 'index' && !preg_match('~^([^?]*?/)?index(\.php)?(?=\?|$)~', $page[0] ?? '')) {
+                    $matches[1] = $indexPage;
+                }
+                if (!preg_match('~^[^?]*?\.php(?=\?|$)~', $page[0] ?? '')) {
+                    $matches[2] = $matches[1] !== '' ? $ext : '';
                 }
 
-                return $matches[1];
-            }, $expectedUrl, 1);
+                return $matches[1] . $matches[2];
+            }, $expectedUrl);
         };
 
+        $app = $this->createApp([
+            'request' => $request,
+            'stickyGetArguments' => $appStickyGetArguments,
+            'urlBuildingIndexPage' => 'default',
+            'urlBuildingExt' => '.php8',
+        ]);
+        $expectedUrlCustom = $makeExpectedUrlFx('default', '.php8');
+        self::assertSame($expectedUrlCustom, $app->url($page, $extraRequestUrlArgs));
+
         $app = $this->createApp([
             'request' => $request,
             'stickyGetArguments' => $appStickyGetArguments,
             'urlBuildingIndexPage' => '',
             'urlBuildingExt' => '',
         ]);
-        $expectedUrlAutoindex = $makeExpectedUrlFx('');
+        $expectedUrlAutoindex = $makeExpectedUrlFx('', '');
         self::assertSame($expectedUrlAutoindex, $app->url($page, $extraRequestUrlArgs));
 
         $app = $this->createApp([
@@ -158,7 +181,7 @@ public function testUrl(string $requestUrl, array $appStickyGetArguments, array
             'urlBuildingIndexPage' => '',
             'urlBuildingExt' => '.html',
         ]);
-        $expectedUrlAutoindex2 = $makeExpectedUrlFx('.html');
+        $expectedUrlAutoindex2 = $makeExpectedUrlFx('', '.html');
         self::assertSame($expectedUrlAutoindex2, $app->url($page, $extraRequestUrlArgs));
     }
 }
diff --git a/tests/CallbackTest.php b/tests/CallbackTest.php
index b4eaacf158..9f8d75a30c 100644
--- a/tests/CallbackTest.php
+++ b/tests/CallbackTest.php
@@ -89,8 +89,8 @@ public function testViewUrlCallback(): void
         $this->simulateCallbackTriggering($cbApp);
         $this->simulateCallbackTriggering($cb);
 
-        $expectedUrlCbApp = 'index.php?' . Callback::URL_QUERY_TRIGGER_PREFIX . 'aa=callback&' . Callback::URL_QUERY_TARGET . '=aa';
-        $expectedUrlCb = 'index.php?' . /* Callback::URL_QUERY_TRIGGER_PREFIX . 'aa=1&' . */ Callback::URL_QUERY_TRIGGER_PREFIX . 'bb=callback&' . Callback::URL_QUERY_TARGET . '=bb';
+        $expectedUrlCbApp = '/index.php?' . Callback::URL_QUERY_TRIGGER_PREFIX . 'aa=callback&' . Callback::URL_QUERY_TARGET . '=aa';
+        $expectedUrlCb = '/index.php?' . /* Callback::URL_QUERY_TRIGGER_PREFIX . 'aa=1&' . */ Callback::URL_QUERY_TRIGGER_PREFIX . 'bb=callback&' . Callback::URL_QUERY_TARGET . '=bb';
         self::assertSame($expectedUrlCbApp, $cbApp->getUrl());
         self::assertSame($expectedUrlCb, $cb->getUrl());