diff --git a/backend/Cargo.lock b/backend/Cargo.lock
index cdb3d4a..cbff620 100644
--- a/backend/Cargo.lock
+++ b/backend/Cargo.lock
@@ -192,6 +192,7 @@ dependencies = [
  "dotenvy",
  "futures-util",
  "lazy-regex",
+ "mime_guess",
  "opendal",
  "rand 0.10.1",
  "serde",
diff --git a/backend/Cargo.toml b/backend/Cargo.toml
index e65fa22..d20da21 100644
--- a/backend/Cargo.toml
+++ b/backend/Cargo.toml
@@ -21,6 +21,7 @@ opendal = { version = "0.56.0", features = ["tests", "services-fs"] }
 argon2 = "0.5.3"
 rand = "0.10.1"
 futures-util = "0.3.32"
+mime_guess = "2.0.5"
 
 [dev-dependencies]
 axum-test = "20.0.0"
diff --git a/backend/src/model.rs b/backend/src/model.rs
index ccbc64c..9c9ac0a 100644
--- a/backend/src/model.rs
+++ b/backend/src/model.rs
@@ -90,7 +90,7 @@ impl FileRepository {
             "#,
             user_id,
             file_name,
-            "TODO-file_type".to_string(),
+            mime_guess::from_path(file_name).first_or_octet_stream().to_string(),
             file_size as i64,
             file_storage_key
         )
@@ -328,7 +328,7 @@ mod tests {
     }
 
     async fn file_repository() -> Result<FileRepository, LoftError> {
-        dotenvy::dotenv().ok();
+        dotenvy::from_filename(".env.test").ok();
         let database_url = std::env::var("DATABASE_URL").expect("DATABASE_URL must be set");
         let pool = PgPool::connect(&database_url).await.unwrap();
         Ok(FileRepository::new(pool)?)
@@ -475,7 +475,7 @@ mod tests {
     }
 
     async fn user_repository() -> Result<UserRepository, LoftError> {
-        dotenvy::dotenv().ok();
+        dotenvy::from_filename(".env.test").ok();
         let database_url = std::env::var("DATABASE_URL").expect("DATABASE_URL must be set");
         let pool = PgPool::connect(&database_url).await.unwrap();
         Ok(UserRepository::new(pool)?)