diff --git a/models/user.go b/models/user.go
index e6717aecd..f4c5b669c 100644
--- a/models/user.go
+++ b/models/user.go
@@ -240,7 +240,7 @@ func (u *User) GenerateRandomAvatar() error {
 }
 
 func (u *User) RelAvatarLink() string {
-	defaultImgUrl := "/img/avatar_default.jpg"
+	defaultImgUrl := "/img/avatar_default.png"
 	if u.Id == -1 {
 		return defaultImgUrl
 	}
diff --git a/modules/base/tool.go b/modules/base/tool.go
index 22a90daff..f045cb227 100644
--- a/modules/base/tool.go
+++ b/modules/base/tool.go
@@ -207,7 +207,7 @@ func HashEmail(email string) string {
 // AvatarLink returns avatar link by given email.
 func AvatarLink(email string) string {
 	if setting.DisableGravatar || setting.OfflineMode {
-		return setting.AppSubUrl + "/img/avatar_default.jpg"
+		return setting.AppSubUrl + "/img/avatar_default.png"
 	}
 
 	return setting.GravatarSource + HashEmail(email)
diff --git a/public/img/avatar_default.jpg b/public/img/avatar_default.jpg
deleted file mode 100644
index f97aaaf04..000000000
Binary files a/public/img/avatar_default.jpg and /dev/null differ
diff --git a/public/img/avatar_default.png b/public/img/avatar_default.png
new file mode 100644
index 000000000..fed568a12
Binary files /dev/null and b/public/img/avatar_default.png differ