diff --git a/.php_cs.dist b/.php_cs.dist
index 2d410bb..d7b95fb 100644
--- a/.php_cs.dist
+++ b/.php_cs.dist
@@ -23,7 +23,7 @@ return PhpCsFixer\Config::create()
         ],
         'linebreak_after_opening_tag' => true,
         'declare_strict_types' => true,
-        'mb_str_functions' => true,
+        'mb_str_functions' => false,
         'no_php4_constructor' => true,
         'no_superfluous_phpdoc_tags' => false,
         'no_unreachable_default_argument_value' => true,
diff --git a/src/ImageExtension.php b/src/ImageExtension.php
index 07f20cd..0d1ddfd 100644
--- a/src/ImageExtension.php
+++ b/src/ImageExtension.php
@@ -244,12 +244,16 @@ private function createImage(
             foreach ($additionalTypes as $extension => $type) {
                 $srcset = null;
 
-                if (isset($attributes['src'])) {
+                if (isset($attributes['src']) && (!isset($attributes['srcset']) || false === strpos($attributes['srcset'], $attributes['src'] . ' '))) {
                     $srcset = $this->addExtension($attributes['src'], $extension);
                 }
 
                 if (isset($attributes['srcset'])) {
-                    $srcset .= ', ' . $this->addExtension($attributes['srcset'], $extension);
+                    if ($srcset) {
+                        $srcset .= ', ';
+                    }
+
+                    $srcset .= $this->addExtension($attributes['srcset'], $extension);
                 }
 
                 if ($srcset) {
diff --git a/tests/Unit/ImageExtensionTest.php b/tests/Unit/ImageExtensionTest.php
index cfba564..892ddff 100644
--- a/tests/Unit/ImageExtensionTest.php
+++ b/tests/Unit/ImageExtensionTest.php
@@ -162,6 +162,64 @@ public function testPictureTag(): void
         );
     }
 
+    public function testComplexWebpPictureTag(): void
+    {
+        $imageExtension = new ImageExtension(null, [], ['webp' => 'image/webp']);
+
+        $this->assertSame(
+            '<picture>' .
+            '<source srcset="/uploads/media/sulu-100x100/01/image.webp?v=1-0 460w, /uploads/media/sulu-170x170/01/image.webp?v=1-0 800w, /uploads/media/sulu-400x400/01/image.webp?v=1-0 1024w"' .
+            ' type="image/webp">' .
+            '<img alt="Logo"' .
+            ' title="Description"' .
+            ' src="/uploads/media/sulu-400x400/01/image.jpg?v=1-0"' .
+            ' srcset="/uploads/media/sulu-100x100/01/image.jpg?v=1-0 460w, /uploads/media/sulu-170x170/01/image.jpg?v=1-0 800w, /uploads/media/sulu-400x400/01/image.jpg?v=1-0 1024w"' .
+            ' sizes="(max-width: 1024px) 100vw, (max-width: 800px) 100vw, 100vw"' .
+            ' id="image-id"' .
+            ' class="image-class">' .
+            '</picture>',
+            $imageExtension->getImage(
+                $this->image,
+                [
+                    'src' => 'sulu-400x400',
+                    'srcset' => 'sulu-100x100 460w, sulu-170x170 800w, sulu-400x400 1024w',
+                    'sizes' => '(max-width: 1024px) 100vw, (max-width: 800px) 100vw, 100vw',
+                    'id' => 'image-id',
+                    'class' => 'image-class',
+                    'alt' => 'Logo',
+                ]
+            )
+        );
+    }
+
+    public function testComplexWebpPictureTagRetina(): void
+    {
+        $imageExtension = new ImageExtension(null, [], ['webp' => 'image/webp']);
+
+        $this->assertSame(
+            '<picture>' .
+            '<source srcset="/uploads/media/sulu-100x100/01/image.webp?v=1-0 1x, /uploads/media/sulu-400x400/01/image.webp?v=1-0 2x"' .
+            ' type="image/webp">' .
+            '<img alt="Logo"' .
+            ' title="Description"' .
+            ' src="/uploads/media/sulu-100x100/01/image.jpg?v=1-0"' .
+            ' srcset="/uploads/media/sulu-100x100/01/image.jpg?v=1-0 1x, /uploads/media/sulu-400x400/01/image.jpg?v=1-0 2x"' .
+            ' id="image-id"' .
+            ' class="image-class">' .
+            '</picture>',
+            $imageExtension->getImage(
+                $this->image,
+                [
+                    'src' => 'sulu-100x100',
+                    'srcset' => 'sulu-100x100 1x, sulu-400x400 2x',
+                    'id' => 'image-id',
+                    'class' => 'image-class',
+                    'alt' => 'Logo',
+                ]
+            )
+        );
+    }
+
     public function testPictureTagMinimalImage(): void
     {
         $imageExtension = new ImageExtension('/lazy');