diff --git a/controllers/threads_controller.go b/controllers/threads_controller.go
index a683d0c..be922e2 100644
--- a/controllers/threads_controller.go
+++ b/controllers/threads_controller.go
@@ -7,6 +7,7 @@ import (
 	"net/http"
 	"path/filepath"
 	"strconv"
+	"strings"
 
 	"github.com/gin-gonic/gin"
 
@@ -127,25 +128,26 @@ func CreateThread(c *gin.Context) {
 	}
 
 	for _, fileInRequest := range filesInRequest {
-		path := filepath.Join(
-			Utils.UPLOADS_DIR_PATH,
-			strconv.Itoa(postID),
-			fileInRequest.Filename,
-		)
 		file := Repositories.File{
 			PostID: postID,
 			Name:   fileInRequest.Filename,
-			Ext:    fileInRequest.Header["Content-Type"][0],
-			Size:   int(fileInRequest.Size),
+			// image/jpeg -> jpeg
+			Ext:  strings.Split(fileInRequest.Header["Content-Type"][0], "/")[1],
+			Size: int(fileInRequest.Size),
 		}
 
-		err := Repositories.Files.CreateInTx(tx, file)
+		fileID, err := Repositories.Files.CreateInTx(tx, file)
 		if err != nil {
 			log.Println("error:", err)
 			c.HTML(http.StatusInternalServerError, "500.html", nil)
 			return
 		}
 
+		path := filepath.Join(
+			Utils.UPLOADS_DIR_PATH,
+			strconv.Itoa(postID),
+			strconv.Itoa(fileID)+"."+file.Ext,
+		)
 		err = c.SaveUploadedFile(fileInRequest, path)
 		if err != nil {
 			log.Println("error:", err)
@@ -217,25 +219,26 @@ func UpdateThread(c *gin.Context) {
 	}
 
 	for _, fileInRequest := range filesInRequest {
-		path := filepath.Join(
-			Utils.UPLOADS_DIR_PATH,
-			strconv.Itoa(threadID),
-			fileInRequest.Filename,
-		)
 		file := Repositories.File{
 			PostID: postID,
 			Name:   fileInRequest.Filename,
-			Ext:    fileInRequest.Header["Content-Type"][0],
-			Size:   int(fileInRequest.Size),
+			// image/jpeg -> jpeg
+			Ext:  strings.Split(fileInRequest.Header["Content-Type"][0], "/")[1],
+			Size: int(fileInRequest.Size),
 		}
 
-		err := Repositories.Files.CreateInTx(tx, file)
+		fileID, err := Repositories.Files.CreateInTx(tx, file)
 		if err != nil {
 			log.Println("error:", err)
 			c.HTML(http.StatusInternalServerError, "500.html", nil)
 			return
 		}
 
+		path := filepath.Join(
+			Utils.UPLOADS_DIR_PATH,
+			strconv.Itoa(threadID),
+			strconv.Itoa(fileID)+"."+file.Ext,
+		)
 		err = c.SaveUploadedFile(fileInRequest, path)
 		if err != nil {
 			log.Println("error:", err)
diff --git a/repositories/files_repository.go b/repositories/files_repository.go
index 3169408..dbf4c2e 100644
--- a/repositories/files_repository.go
+++ b/repositories/files_repository.go
@@ -32,7 +32,7 @@ func (r *FilesRepository) Create(f File) error {
 
 func (r *FilesRepository) GetByPostIDs(postIDs []int) (map[int][]File, error) {
 	sql := `
-		SELECT post_id, name, size
+		SELECT id, post_id, name, size, ext
 		FROM files
 		WHERE post_id = ANY ($1)
 		ORDER BY id ASC
@@ -52,7 +52,7 @@ func (r *FilesRepository) GetByPostIDs(postIDs []int) (map[int][]File, error) {
 	filesMapByPostId := make(map[int][]File)
 	for rows.Next() {
 		var file File
-		err = rows.Scan(&file.PostID, &file.Name, &file.Size)
+		err = rows.Scan(&file.ID, &file.PostID, &file.Name, &file.Size, &file.Ext)
 		if err != nil {
 			return nil, err
 		}
@@ -70,20 +70,22 @@ func (r *FilesRepository) GetByPostIDs(postIDs []int) (map[int][]File, error) {
 	return filesMapByPostId, nil
 }
 
-func (r *FilesRepository) CreateInTx(tx pgx.Tx, f File) error {
+func (r *FilesRepository) CreateInTx(tx pgx.Tx, f File) (int, error) {
 	sql := `
 		INSERT INTO files (post_id, name, ext, size)
 		VALUES ($1, $2, $3, $4)
+		RETURNING id
 	`
 
 	row := tx.QueryRow(
 		context.TODO(), sql, f.PostID, f.Name, f.Ext, f.Size,
 	)
 
-	err := row.Scan()
+	createdFile := new(File)
+	err := row.Scan(&createdFile.ID)
 	if err != nil && err != pgx.ErrNoRows {
-		return err
+		return 0, err
 	}
 
-	return nil
+	return createdFile.ID, nil
 }
diff --git a/templates/index.html b/templates/index.html
index 9d2124d..e4d6427 100644
--- a/templates/index.html
+++ b/templates/index.html
@@ -24,7 +24,7 @@
           {{ if gt $length 0 }}
           {{ $FirstFile := index $Post.Files 0 }}
           <img 
-            src="/uploads/{{$Post.ID}}/{{$FirstFile.Name}}" 
+            src="/uploads/{{$Post.ID}}/{{$FirstFile.ID}}.{{$FirstFile.Ext}}" 
             class="card-img-top"
             alt="Uploaded picture"
           >
diff --git a/templates/thread.html b/templates/thread.html
index 175d13b..dd16646 100644
--- a/templates/thread.html
+++ b/templates/thread.html
@@ -20,7 +20,7 @@
           {{ $length := len $Post.Files }} {{ if gt $length 0 }}
           {{$FirstFile := index $Post.Files 0}}
           <img 
-            src="/uploads/{{$FirstPost.ID}}/{{$FirstFile.Name}}" 
+            src="/uploads/{{$FirstPost.ID}}/{{$FirstFile.ID}}.{{$FirstFile.Ext}}" 
             class="card-img-top"
             alt="Uploaded picture"
           >