diff --git a/src/CP/Navigation/NavItem.php b/src/CP/Navigation/NavItem.php
index 7e860638293..dfb95673911 100644
--- a/src/CP/Navigation/NavItem.php
+++ b/src/CP/Navigation/NavItem.php
@@ -292,6 +292,14 @@ protected function currentUrlIsRestfulDescendant(): bool
         ]);
     }
 
+    /**
+     * Check if we should assume nested URL conventions for active state on children.
+     */
+    protected function doesntHaveExplicitChildren(): bool
+    {
+        return (bool) ! $this->children;
+    }
+
     /**
      * Check if this nav item was ever a child before user preferences were applied.
      */
@@ -393,6 +401,7 @@ public function isActive()
         if ($this->currentUrlIsNotExplicitlyReferencedInNav()) {
             switch (true) {
                 case $this->currentUrlIsRestfulDescendant():
+                case $this->doesntHaveExplicitChildren():
                 case $this->wasOriginallyChild():
                     return $this->isActiveByPattern($this->active);
             }
diff --git a/tests/CP/Navigation/ActiveNavItemTest.php b/tests/CP/Navigation/ActiveNavItemTest.php
index ab560f7ddf1..d59d9f4ac0d 100644
--- a/tests/CP/Navigation/ActiveNavItemTest.php
+++ b/tests/CP/Navigation/ActiveNavItemTest.php
@@ -536,6 +536,25 @@ public function it_properly_handles_various_edge_cases_when_checking_is_active_o
         $this->assertFalse($externalSecure->isActive());
     }
 
+    #[Test]
+    public function active_nav_descendant_url_still_functions_properly_when_parent_item_has_no_children()
+    {
+        Facades\CP\Nav::extend(function ($nav) {
+            $nav->tools('Schopify')->url('/cp/totally-custom-url');
+        });
+
+        $this
+            ->prepareNavCaches()
+            ->get('http://localhost/cp/totally-custom-url/deeper/descendant')
+            ->assertStatus(200);
+
+        $toolsItems = $this->build()->get('Tools');
+
+        $this->assertTrue($this->getItemByDisplay($toolsItems, 'Schopify')->isActive());
+        $this->assertFalse($this->getItemByDisplay($toolsItems, 'Addons')->isActive());
+        $this->assertFalse($this->getItemByDisplay($toolsItems, 'Utilities')->isActive());
+    }
+
     #[Test]
     public function active_nav_check_still_functions_properly_when_custom_nav_extension_hijacks_a_core_item_child()
     {