diff --git a/examples/filters.php b/examples/filters.php
index 588561c..9ff481d 100644
--- a/examples/filters.php
+++ b/examples/filters.php
@@ -1,15 +1,17 @@
 <?php
 
-use Opdavies\GmailFilterBuilder\Filter;
+use Opdavies\GmailFilterBuilder\Model\Filter;
 
-require_once __DIR__ . '/vendor/autoload.php';
+require_once __DIR__ . '/../vendor/autoload.php';
 
 return [
     Filter::create()
-        ->from('foo@example.com')
-        ->labelAndArchive('Example'),
+        ->from('papercall.io')
+        ->subject('New Submission For Drupal Camp Bristol 2019')
+        ->labelAndArchive('DrupalCamp Bristol'),
 
-    Filter::create()
-        ->from('bar@example.com')
-        ->important(),
+    ($filter = Filter::create())
+        ->from('papercall.io')
+        ->negate($filter->subject('New Submission For Drupal Camp Bristol 2019'))
+        ->labelAndArchive('Deletable/Other notifications'),
 ];
diff --git a/src/Model/Filter.php b/src/Model/Filter.php
index 76b14ff..5ac96d0 100644
--- a/src/Model/Filter.php
+++ b/src/Model/Filter.php
@@ -275,4 +275,22 @@ class Filter
     {
         return $this->properties;
     }
+
+    public function negate(Filter $filter): self
+    {
+        $filter->properties = collect($filter->toArray())
+            ->mapWithKeys(function ($conditions, $key) {
+                return [$key => collect($conditions)->map(function ($condition) {
+                    return $this->negateCondition($condition);
+                })];
+            })
+            ->toArray();
+
+        return $this;
+    }
+
+    private function negateCondition(string $condition): string
+    {
+        return "-($condition)";
+    }
 }
diff --git a/tests/Unit/Model/FilterTest.php b/tests/Unit/Model/FilterTest.php
index 57e7223..02998e0 100644
--- a/tests/Unit/Model/FilterTest.php
+++ b/tests/Unit/Model/FilterTest.php
@@ -337,4 +337,20 @@ class FilterTest extends TestCase
                 ->toArray()
         );
     }
+
+    /** @test */
+    public function conditions_can_be_negated()
+    {
+        $this->filter
+            ->from('example.com')
+            ->negate($this->filter->subject('test'));
+
+        $this->assertEquals(
+            [
+                'from' => 'example.com',
+                'subject' => '-(test)',
+            ],
+            $this->filter->toArray()
+        );
+    }
 }