diff --git a/inc/Service/Media/ThumbGenerator.php b/inc/Service/Media/ThumbGenerator.php
index ce7ec60e..0e5fbfbe 100644
--- a/inc/Service/Media/ThumbGenerator.php
+++ b/inc/Service/Media/ThumbGenerator.php
@@ -16,5 +16,5 @@ interface ThumbGenerator {
 	 * @param int $max_height
 	 * @return ThumbGenerationResult
 	 */
-	public function generateThumb(string $source_file_path, string $preferred_out_file_path, int $max_width, int $max_height): ThumbGenerationResult;
+	public function generateThumb(string $source_file_path, string $source_file_mime, string $preferred_out_file_path, int $max_width, int $max_height): ThumbGenerationResult;
 }