diff --git a/src/thumbnail.rs b/src/thumbnail.rs
index 042ecde..109d1cd 100644
--- a/src/thumbnail.rs
+++ b/src/thumbnail.rs
@@ -30,7 +30,7 @@ pub fn parse_file_path(requested_path: &str) -> (String, u32, String) {
     // пытаемся извлечь формат из имени файла
     if let Some(filename_part) = path_parts.pop() {
         if let Some((base, ext_part)) = filename_part.rsplit_once('.') {
-            extension = ext_part.to_lowercase();
+            extension = ext_part.to_string();
             base_filename = base.to_string(); // Устанавливаем base_filename без расширения
         } else {
             base_filename = filename_part.to_string();
@@ -41,7 +41,7 @@ pub fn parse_file_path(requested_path: &str) -> (String, u32, String) {
     if base_filename.is_empty() {
         if let Some(filename_part) = path_parts.pop() {
             if let Some((base, ext_part)) = filename_part.rsplit_once('.') {
-                extension = ext_part.to_lowercase();
+                extension = ext_part.to_string();
                 base_filename = base.to_string();
             } else {
                 base_filename = filename_part.to_string();