diff --git a/src/Contracts/Imaging/UrlBuilder.php b/src/Contracts/Imaging/UrlBuilder.php
index 937df59503..4ea839f27e 100644
--- a/src/Contracts/Imaging/UrlBuilder.php
+++ b/src/Contracts/Imaging/UrlBuilder.php
@@ -9,8 +9,7 @@ interface UrlBuilder
      *
      * @param  \Statamic\Contracts\Assets\Asset|string  $item
      * @param  array  $params
-     * @param  string|null  $filename
      * @return string
      */
-    public function build($item, $params, $filename = null);
+    public function build($item, $params);
 }
diff --git a/src/Imaging/GlideImageManipulator.php b/src/Imaging/GlideImageManipulator.php
index 31a468d1f7..8c4589a52d 100644
--- a/src/Imaging/GlideImageManipulator.php
+++ b/src/Imaging/GlideImageManipulator.php
@@ -31,13 +31,6 @@ class GlideImageManipulator implements ImageManipulator
      */
     protected $item_type;
 
-    /**
-     * A custom filename.
-     *
-     * @var string|null
-     */
-    protected $filename;
-
     /**
      * Methods available in Glide's API.
      *
@@ -106,20 +99,7 @@ public function item($item)
      */
     public function build()
     {
-        return $this->builder->build($this->item, $this->params, $this->filename);
-    }
-
-    /**
-     * Set a custom filename.
-     *
-     * @param  string  $filename
-     * @return $this
-     */
-    public function filename($filename)
-    {
-        $this->filename = $filename;
-
-        return $this;
+        return $this->builder->build($this->item, $this->params);
     }
 
     /**
diff --git a/src/Imaging/GlideUrlBuilder.php b/src/Imaging/GlideUrlBuilder.php
index fe7afa2068..36916511b2 100644
--- a/src/Imaging/GlideUrlBuilder.php
+++ b/src/Imaging/GlideUrlBuilder.php
@@ -30,26 +30,20 @@ public function __construct(array $options = [])
      *
      * @throws \Exception
      */
-    public function build($item, $params, $filename = null)
+    public function build($item, $params)
     {
         $this->item = $item;
 
+        $filename = null;
+
         switch ($this->itemType()) {
             case 'url':
                 $path = 'http/'.base64_encode($item);
-
-                if (! $filename) {
-                    $filename = Str::afterLast($item, '/');
-                }
-
+                $filename = Str::afterLast($item, '/');
                 break;
             case 'asset':
                 $path = 'asset/'.base64_encode($this->item->containerId().'/'.$this->item->path());
-
-                if (! $filename) {
-                    $filename = Str::afterLast($this->item->path(), '/');
-                }
-
+                $filename = Str::afterLast($this->item->path(), '/');
                 break;
             case 'id':
                 $path = 'asset/'.base64_encode(str_replace('::', '/', $this->item));
diff --git a/src/Imaging/StaticUrlBuilder.php b/src/Imaging/StaticUrlBuilder.php
index de9e4f9f37..87bf8984d5 100644
--- a/src/Imaging/StaticUrlBuilder.php
+++ b/src/Imaging/StaticUrlBuilder.php
@@ -44,10 +44,9 @@ public function __construct(ImageGenerator $generator, array $options = [])
      *
      * @param  \Statamic\Contracts\Assets\Asset|string  $item
      * @param  array  $params
-     * @param  string|null  $filename
      * @return string
      */
-    public function build($item, $params, $filename = null)
+    public function build($item, $params)
     {
         $this->item = $item;
         $this->params = $params;
diff --git a/tests/Imaging/GlideUrlBuilderTest.php b/tests/Imaging/GlideUrlBuilderTest.php
index 1ebd12b5e3..a1dcb42df6 100644
--- a/tests/Imaging/GlideUrlBuilderTest.php
+++ b/tests/Imaging/GlideUrlBuilderTest.php
@@ -72,14 +72,6 @@ public function testId()
         );
     }
 
-    public function testFilename()
-    {
-        $this->assertEquals(
-            '/img/foo.jpg/custom.png?w=100',
-            $this->builder->build('/foo.jpg', ['w' => '100'], 'custom.png')
-        );
-    }
-
     public function testConfigAddsFilename()
     {
         $asset = new Asset;