diff --git a/src/wp-includes/customize/class-wp-customize-media-control.php b/src/wp-includes/customize/class-wp-customize-media-control.php
index 3bdc4e2dc1..ba8d8e9d31 100644
--- a/src/wp-includes/customize/class-wp-customize-media-control.php
+++ b/src/wp-includes/customize/class-wp-customize-media-control.php
@@ -99,7 +99,7 @@ class WP_Customize_Media_Control extends WP_Customize_Control {
 					'id'    => 1,
 					'url'   => $this->setting->default,
 					'type'  => $type,
-					'icon'  => wp_mime_type_icon( $type ),
+					'icon'  => wp_mime_type_icon( $type, '.svg' ),
 					'title' => wp_basename( $this->setting->default ),
 				);
 
diff --git a/src/wp-includes/deprecated.php b/src/wp-includes/deprecated.php
index 45b4f89a9e..4de4a93039 100644
--- a/src/wp-includes/deprecated.php
+++ b/src/wp-includes/deprecated.php
@@ -1910,7 +1910,7 @@ function get_attachment_icon_src( $id = 0, $fullsize = false ) {
 
 		$src = wp_get_attachment_url( $post->ID );
 		$src_file = & $file;
-	} elseif ( $src = wp_mime_type_icon( $post->ID ) ) {
+	} elseif ( $src = wp_mime_type_icon( $post->ID, '.svg' ) ) {
 		// No thumb, no image. We'll look for a mime-related icon instead.
 
 		/** This filter is documented in wp-includes/post.php */
diff --git a/src/wp-includes/media.php b/src/wp-includes/media.php
index b5e477e7f7..5fb5a27230 100644
--- a/src/wp-includes/media.php
+++ b/src/wp-includes/media.php
@@ -972,14 +972,22 @@ function wp_get_attachment_image_src( $attachment_id, $size = 'thumbnail', $icon
 		$src = false;
 
 		if ( $icon ) {
-			$src = wp_mime_type_icon( $attachment_id );
+			$src = wp_mime_type_icon( $attachment_id, '.svg' );
 
 			if ( $src ) {
 				/** This filter is documented in wp-includes/post.php */
 				$icon_dir = apply_filters( 'icon_dir', ABSPATH . WPINC . '/images/media' );
 
-				$src_file               = $icon_dir . '/' . wp_basename( $src );
+				$src_file = $icon_dir . '/' . wp_basename( $src );
 				list( $width, $height ) = wp_getimagesize( $src_file );
+				$ext      = strtolower( substr( $src_file, -4 ) );
+				if ( '.svg' === $ext ) {
+					// SVG does not have true dimensions, so this assigns width and height directly.
+					$width  = 48;
+					$height = 64;
+				} else {
+					list( $width, $height ) = wp_getimagesize( $src_file );
+				}
 			}
 		}
 
@@ -3067,7 +3075,7 @@ function wp_playlist_shortcode( $attr ) {
 				list( $src, $width, $height ) = wp_get_attachment_image_src( $thumb_id, 'thumbnail' );
 				$track['thumb']               = compact( 'src', 'width', 'height' );
 			} else {
-				$src            = wp_mime_type_icon( $attachment->ID );
+				$src            = wp_mime_type_icon( $attachment->ID, '.svg' );
 				$width          = 48;
 				$height         = 64;
 				$track['image'] = compact( 'src', 'width', 'height' );
@@ -4339,7 +4347,7 @@ function wp_prepare_attachment_for_js( $attachment ) {
 		'mime'          => $attachment->post_mime_type,
 		'type'          => $type,
 		'subtype'       => $subtype,
-		'icon'          => wp_mime_type_icon( $attachment->ID ),
+		'icon'          => wp_mime_type_icon( $attachment->ID, '.svg' ),
 		'dateFormatted' => mysql2date( __( 'F j, Y' ), $attachment->post_date ),
 		'nonces'        => array(
 			'update' => false,
@@ -4510,7 +4518,7 @@ function wp_prepare_attachment_for_js( $attachment ) {
 			list( $src, $width, $height ) = wp_get_attachment_image_src( $id, 'thumbnail' );
 			$response['thumb']            = compact( 'src', 'width', 'height' );
 		} else {
-			$src               = wp_mime_type_icon( $attachment->ID );
+			$src               = wp_mime_type_icon( $attachment->ID, '.svg' );
 			$width             = 48;
 			$height            = 64;
 			$response['image'] = compact( 'src', 'width', 'height' );
diff --git a/src/wp-includes/post.php b/src/wp-includes/post.php
index 04fb143a1d..d035acb045 100644
--- a/src/wp-includes/post.php
+++ b/src/wp-includes/post.php
@@ -6803,10 +6803,11 @@ function wp_attachment_is_image( $post = null ) {
  *
  * @since 2.1.0
  *
- * @param string|int $mime MIME type or attachment ID.
+ * @param string|int $mime          MIME type or attachment ID.
+ * @param string     $preferred_ext File format to prefer in return. Default .png.
  * @return string|false Icon, false otherwise.
  */
-function wp_mime_type_icon( $mime = 0 ) {
+function wp_mime_type_icon( $mime = 0, $preferred_ext = '.png' ) {
 	if ( ! is_numeric( $mime ) ) {
 		$icon = wp_cache_get( "mime_type_icon_$mime" );
 	}
@@ -6885,7 +6886,9 @@ function wp_mime_type_icon( $mime = 0 ) {
 							}
 							continue;
 						}
-						$icon_files[ "$dir/$file" ] = "$uri/$file";
+						if ( $ext === $preferred_ext ) {
+							$icon_files[ "$dir/$file" ] = "$uri/$file";
+						}
 					}
 					closedir( $dh );
 				}
diff --git a/tests/phpunit/tests/media.php b/tests/phpunit/tests/media.php
index 8d91517b1f..7cc9f5470f 100644
--- a/tests/phpunit/tests/media.php
+++ b/tests/phpunit/tests/media.php
@@ -399,7 +399,7 @@ https://w.org</a>',
 		$this->assertSame( '', $prepped['subtype'] );
 		// #21963, there will be a GUID always, so there will be a URL.
 		$this->assertNotEquals( '', $prepped['url'] );
-		$this->assertSame( site_url( 'wp-includes/images/media/default.png' ), $prepped['icon'] );
+		$this->assertSame( site_url( 'wp-includes/images/media/default.svg' ), $prepped['icon'] );
 
 		// Fake a mime.
 		$post->post_mime_type = 'image/jpeg';