diff --git a/src/commands/challenge.rs b/src/commands/challenge.rs
index 945b075..84c90d0 100644
--- a/src/commands/challenge.rs
+++ b/src/commands/challenge.rs
@@ -149,11 +149,17 @@ pub async fn submit(ctx: Context<'_>, submission: serenity::Attachment) -> Resul
             break;
         }
     }
+    let username = if author.discriminator == 0 { // new usernames
+        author.name.clone()
+    } else {
+        format!("{}#{}", author.name, author.discriminator)
+    };
+    let username = &username;
     if !existing_submitter {
         let mut submitter_data = Map::new();
         submitter_data.insert(
             String::from("username"),
-            format!("{}#{}", author.name, author.discriminator).into(),
+            username.clone().into(),
         );
         let mut images: Vec<String> = Vec::new();
         for (i, attachment) in attachments.iter().enumerate() {
@@ -173,10 +179,9 @@ pub async fn submit(ctx: Context<'_>, submission: serenity::Attachment) -> Resul
             }
             requires_rebuild = true;
             let file_name = format!(
-                "{}-{}-{}-{}{}.{}",
+                "{}-{}-{}{}.{}",
                 submission_data.len() + 1,
                 slugify(&author.name),
-                author.discriminator,
                 timestamp,
                 if i == 0 {
                     "".to_owned()
@@ -256,7 +261,6 @@ pub async fn submit(ctx: Context<'_>, submission: serenity::Attachment) -> Resul
                 channel
                     .send_message(&ctx.serenity_context().http, |m| {
                         m.embed(|e| {
-                            let username = format!("{}#{}", author.name, author.discriminator);
                             let domain = get_domain();
                             let n = get_challenge_number();
                             let mut description = format!(
diff --git a/src/utils.rs b/src/utils.rs
index bcae7f5..cc74f61 100644
--- a/src/utils.rs
+++ b/src/utils.rs
@@ -67,6 +67,10 @@ pub fn get_submission_data(challenge: i32) -> Vec<Value> {
             json
         }
         Err(ref e) if e.kind() == std::io::ErrorKind::NotFound => {
+            // Create parent directory if not exists
+            if let Some(parent_dir) = std::path::Path::new(&submission_data_path).parent() {
+                fs::create_dir_all(parent_dir).unwrap();
+            }
             let mut file = File::create(&submission_data_path).unwrap();
             file.write_all(b"[]").unwrap();
             file.flush().unwrap();
@@ -371,7 +375,7 @@ pub async fn leaderboard(ctx: &Context<'_>) -> Result<(), Error> {
     let mut top_submitters: Vec<(&String, &u32)> = submission_counts.iter().collect();
     top_submitters.sort_by(|a, b| b.1.cmp(a.1));
     let mut leaderboard_html = String::from("<table id=\"leaderboard\">");
-    for (i, (id, count)) in top_submitters[0..LENGTH].iter().enumerate() {
+    for (i, (id, count)) in top_submitters[0..std::cmp::min(top_submitters.len(), LENGTH)].iter().enumerate() {
         let place = i + 1;
         let user = serenity::UserId(id.parse::<u64>().unwrap())
             .to_user(&ctx.serenity_context().http)
@@ -380,7 +384,12 @@ pub async fn leaderboard(ctx: &Context<'_>) -> Result<(), Error> {
         let profile = format!("https://discord.com/users/{id}");
         let name = &user.name;
         let discriminator = user.discriminator;
-        leaderboard_html.push_str(&format!("<tr><td>{place}</td><td><a href=\"{profile}\" target=\"_blank\" class=\"no-underline\"><img src=\"{avatar}\" onerror=\"this.src='/default.png'\"> <span class=\"underline\">{name}<span class=\"muted\">#{:0>4}</span></span></a></td><td>{count}</td></tr>", discriminator));
+        leaderboard_html.push_str(&format!("<tr><td>{place}</td><td><a href=\"{profile}\" target=\"_blank\" class=\"no-underline\"><img src=\"{avatar}\" onerror=\"this.src='/default.png'\"> <span class=\"underline\">{name}"));
+        // New usernames have #0000 discriminator
+        if discriminator != 0 {
+            leaderboard_html.push_str(&format!("<span class=\"muted\">#{:0>4}</span>", discriminator));
+        }
+        leaderboard_html.push_str(&format!("</span></a></td><td>{count}</td></tr>"));
     }
     leaderboard_html.push_str("</table>");
     let mut file = std::fs::OpenOptions::new()