diff --git a/src/Constrict/File.php b/src/Constrict/File.php
index d28f49f..16994ec 100644
--- a/src/Constrict/File.php
+++ b/src/Constrict/File.php
@@ -91,27 +91,7 @@ class File
 	 */
 	private function exif_imageType(): ?int
 	{
-		return match (\exif_imagetype($this->tmp_name)) {
-			IMAGETYPE_GIF                        => '.gif',
-			IMAGETYPE_JPEG                       => '.jpg',
-			IMAGETYPE_PNG                        => '.png',
-			IMAGETYPE_SWF                        => '.swf',
-			IMAGETYPE_PSD                        => '.psd',
-			IMAGETYPE_BMP                        => '.bmp',
-			IMAGETYPE_TIFF_II, IMAGETYPE_TIFF_MM => '.tiff',
-			IMAGETYPE_JPC                        => '.jpc',
-			IMAGETYPE_JP2                        => '.jp2',
-			IMAGETYPE_JPX                        => '.jpx',
-			IMAGETYPE_JB2                        => '.jb2',
-			IMAGETYPE_SWC                        => '.swc',
-			IMAGETYPE_IFF                        => '.iff',
-			IMAGETYPE_WBMP                       => '.wbmp',
-			IMAGETYPE_XBM                        => '.xbm',
-			IMAGETYPE_ICO                        => '.ico',
-			IMAGETYPE_WEBP                       => '.webp',
-			IMAGETYPE_AVIF                       => '.avif',
-			default                              => throw new Exception('未知的图片类型'),
-		};
+		return exif_imagetype($this->tmp_name);
 	}