diff --git a/app/controllers/snippets_controller.rb b/app/controllers/snippets_controller.rb
index e54a968..0dd941a 100644
--- a/app/controllers/snippets_controller.rb
+++ b/app/controllers/snippets_controller.rb
@@ -19,6 +19,9 @@ class SnippetsController < ApplicationController
 
   def user_index
     @user = User.find_by(username: params[:username])
+
+    render_404 and return unless @user
+
     @snippets = @user.snippets.fresh.non_expired
 
     if @user == current_user
--
libgit2 0.21.2