diff --git a/src/Concerns/SortsQuery.php b/src/Concerns/SortsQuery.php
index c61d216f..e96e5a6c 100644
--- a/src/Concerns/SortsQuery.php
+++ b/src/Concerns/SortsQuery.php
@@ -69,7 +69,12 @@ protected function addRequestedSortsToQuery(): void
 
                 $sort = $this->findSort($key);
 
-                $sort?->sort($this, $descending);
+                if (! $sort) {
+                    // Apply default sort if no valid sorts are present in the request
+                    $this->defaultSorts($this->allowedSorts->toArray());
+                } else {
+                    $sort->sort($this, $descending);
+                }
             });
     }
 
diff --git a/tests/SortTest.php b/tests/SortTest.php
index 95534beb..caa6f22e 100644
--- a/tests/SortTest.php
+++ b/tests/SortTest.php
@@ -430,6 +430,21 @@ public function __invoke(Builder $query, bool $descending, string $property): Bu
     $this->assertSortedDescending($sortedModels, 'name');
 });
 
+// Test for issue resolution
+it('applies default sort when all provided sort parameters are invalid', function () {
+    $request = new Request([
+        'sort' => 'invalid_column',
+    ]);
+
+    $sortedModels = QueryBuilder::for(TestModel::class, $request)
+        ->allowedSorts('name')
+        ->defaultSort('-name')
+        ->get();
+
+    // The default sort '-name' should be applied, resulting in models being sorted by 'name' in descending order.
+    $this->assertSortedDescending($sortedModels, 'name');
+});
+
 // Helpers
 function createQueryFromSortRequest(?string $sort = null): QueryBuilder
 {