diff --git a/app/Jobs/ProcessPosterImage.php b/app/Jobs/ProcessPosterImage.php
index e82ea46..fe6920d 100644
--- a/app/Jobs/ProcessPosterImage.php
+++ b/app/Jobs/ProcessPosterImage.php
@@ -24,8 +24,11 @@ class ProcessPosterImage implements ShouldQueue
     public function handle()
     {
         $imageContents = Storage::disk('public')->get($this->concert->poster_image_path);
-        $image = Image::make($imageContents);
-        $image->resize(600)->encode();
+
+        $image = Image::make($imageContents)->resize(600, null, function ($constraint) {
+            $constraint->aspectRatio();
+        })->limitColors(255)->encode();
+
         Storage::disk('public')->put($this->concert->poster_image_path, (string) $image);
     }
 }
diff --git a/tests/Unit/Jobs/ProcessPosterImageTest.php b/tests/Unit/Jobs/ProcessPosterImageTest.php
index ddeb38f..28d1873 100644
--- a/tests/Unit/Jobs/ProcessPosterImageTest.php
+++ b/tests/Unit/Jobs/ProcessPosterImageTest.php
@@ -26,8 +26,35 @@ class ProcessPosterImageTest extends TestCase
         ProcessPosterImage::dispatch($concert);
 
         $resizedImage = Storage::disk('public')->get('posters/example-poster.png');
-        list($width) = getimagesizefromstring($resizedImage);
+        list($width, $height) = getimagesizefromstring($resizedImage);
         $this->assertEquals(600, $width);
+        $this->assertEquals(776, $height);
 
+        $resizedImageContents = Storage::disk('public')->get('posters/example-poster.png');
+        $controlImageContents = file_get_contents(base_path('tests/__fixtures__/optimized-poster.png'));
+        $this->assertEquals($controlImageContents, $resizedImageContents);
+    }
+
+    /** @test */
+    function it_optimizes_the_poster_image()
+    {
+        Storage::fake('public');
+        Storage::disk('public')->put(
+            'posters/example-poster.png',
+            file_get_contents(base_path('tests/__fixtures__/small-unoptimized-poster.png'))
+        );
+        $concert = \ConcertFactory::createUnpublished([
+            'poster_image_path' => 'posters/example-poster.png',
+        ]);
+
+        ProcessPosterImage::dispatch($concert);
+
+        $optimizedImageSize = Storage::disk('public')->size('posters/example-poster.png');
+        $originalSize = filesize(base_path('tests/__fixtures__/small-unoptimized-poster.png'));
+        $this->assertLessThan($originalSize, $optimizedImageSize);
+
+        $optimizedImageContents = Storage::disk('public')->get('posters/example-poster.png');
+        $controlImageContents = file_get_contents(base_path('tests/__fixtures__/optimized-poster.png'));
+        $this->assertEquals($controlImageContents, $optimizedImageContents);
     }
 }
diff --git a/tests/__fixtures__/optimized-poster.png b/tests/__fixtures__/optimized-poster.png
new file mode 100644
index 0000000..4421180
Binary files /dev/null and b/tests/__fixtures__/optimized-poster.png differ
diff --git a/tests/__fixtures__/small-unoptimized-poster.png b/tests/__fixtures__/small-unoptimized-poster.png
new file mode 100644
index 0000000..94b0b82
Binary files /dev/null and b/tests/__fixtures__/small-unoptimized-poster.png differ