diff --git a/src/commands/challenge.rs b/src/commands/challenge.rs
index c665067..940035d 100644
--- a/src/commands/challenge.rs
+++ b/src/commands/challenge.rs
@@ -99,6 +99,7 @@ pub async fn submit(ctx: Context<'_>, submission: serenity::Attachment) -> Resul
     };
     let author = ctx.author();
     let mut submitted_images = Vec::new();
+    let mut is_test = false;
     for submission in submission_data.iter_mut() {
         if is_matching_submission(submission, author) {
             existing_submitter = true;
@@ -110,6 +111,9 @@ pub async fn submit(ctx: Context<'_>, submission: serenity::Attachment) -> Resul
                 .map(|value| value.as_str().unwrap().to_owned())
                 .collect();
             for (i, attachment) in attachments.iter().enumerate() {
+                if attachment.filename.starts_with("_test_submission.") {
+                    is_test = true;
+                }
                 let extension;
                 if let Some(content_type) = &attachment.content_type {
                     if content_type == "image/png" {
@@ -156,6 +160,9 @@ pub async fn submit(ctx: Context<'_>, submission: serenity::Attachment) -> Resul
         submitter_data.insert(String::from("username"), username.clone().into());
         let mut images: Vec<String> = Vec::new();
         for (i, attachment) in attachments.iter().enumerate() {
+            if attachment.filename.starts_with("_test_submission.") {
+                is_test = true;
+            }
             let extension;
             if let Some(content_type) = &attachment.content_type {
                 if content_type == "image/png" {
@@ -227,74 +234,76 @@ pub async fn submit(ctx: Context<'_>, submission: serenity::Attachment) -> Resul
         } else {
             None
         };
-        for image in submitted_images.iter() {
-            for (other_guild_id, data) in guild_data.iter() {
-                let here = other_guild_id.eq(&ctx.guild_id().unwrap().as_u64().to_string());
-                if !here && other_guild_id.eq("116379774825267202") {
-                    // Don't crosspost to 日英
-                    continue;
-                }
-                if !repost_here && here {
-                    continue;
-                }
-                let data = match data.as_object() {
-                    Some(data) => data,
-                    // "suggestionChannel": "..." is at root level,
-                    // and is not an object. Ignore it.
-                    None => continue,
-                };
-                if !data.contains_key("submissionChannel") {
-                    continue;
-                }
-                let channel = serenity::ChannelId(
-                    data["submissionChannel"]
-                        .as_str()
+        if !is_test {
+            for image in submitted_images.iter() {
+                for (other_guild_id, data) in guild_data.iter() {
+                    let here = other_guild_id.eq(&ctx.guild_id().unwrap().as_u64().to_string());
+                    if !here && other_guild_id.eq("116379774825267202") {
+                        // Don't crosspost to 日英
+                        continue;
+                    }
+                    if !repost_here && here {
+                        continue;
+                    }
+                    let data = match data.as_object() {
+                        Some(data) => data,
+                        // "suggestionChannel": "..." is at root level,
+                        // and is not an object. Ignore it.
+                        None => continue,
+                    };
+                    if !data.contains_key("submissionChannel") {
+                        continue;
+                    }
+                    let channel = serenity::ChannelId(
+                        data["submissionChannel"]
+                            .as_str()
+                            .unwrap()
+                            .parse::<u64>()
+                            .unwrap(),
+                    );
+                    let accent_color = ctx
+                        .serenity_context()
+                        .http
+                        .get_user(*author.id.as_u64())
+                        .await
                         .unwrap()
-                        .parse::<u64>()
-                        .unwrap(),
-                );
-                let accent_color = ctx
-                    .serenity_context()
-                    .http
-                    .get_user(*author.id.as_u64())
-                    .await
-                    .unwrap()
-                    .accent_colour;
-                channel
-                    .send_message(&ctx.serenity_context().http, |m| {
-                        m.embed(|e| {
-                            let domain = &ARGS.domain;
-                            let n = get_challenge_number();
-                            let mut description = format!(
-                                "New submission to [Tegaki Tuesday #{n}](https://{domain}/{n})!"
-                            );
-                            if !here {
-                                description.push_str(&if let Some(invite) = invite {
-                                    format!(
-                                        "\nCrossposted from [{}](https://discord.gg/{invite})",
-                                        guild.name
-                                    )
-                                } else {
-                                    format!("\nCrossposted from {}", guild.name)
-                                });
-                            };
-                            e.description(description);
-                            let mut embed_author = serenity::builder::CreateEmbedAuthor::default();
-                            embed_author
-                                .icon_url(get_avatar(author))
-                                .name(username)
-                                .url(format!("https://discord.com/users/{}", author.id));
-                            e.set_author(embed_author);
-                            e.image(format!("https://{domain}/{n}/{image}"));
-                            if let Some(accent_color) = accent_color {
-                                e.color(accent_color);
-                            }
-                            e
-                        });
-                        m
-                    })
-                    .await
-                    .unwrap();
+                        .accent_colour;
+                    channel
+                        .send_message(&ctx.serenity_context().http, |m| {
+                            m.embed(|e| {
+                                let domain = &ARGS.domain;
+                                let n = get_challenge_number();
+                                let mut description = format!(
+                                    "New submission to [Tegaki Tuesday #{n}](https://{domain}/{n})!"
+                                );
+                                if !here {
+                                    description.push_str(&if let Some(invite) = invite {
+                                        format!(
+                                            "\nCrossposted from [{}](https://discord.gg/{invite})",
+                                            guild.name
+                                        )
+                                    } else {
+                                        format!("\nCrossposted from {}", guild.name)
+                                    });
+                                };
+                                e.description(description);
+                                let mut embed_author = serenity::builder::CreateEmbedAuthor::default();
+                                embed_author
+                                    .icon_url(get_avatar(author))
+                                    .name(username)
+                                    .url(format!("https://discord.com/users/{}", author.id));
+                                e.set_author(embed_author);
+                                e.image(format!("https://{domain}/{n}/{image}"));
+                                if let Some(accent_color) = accent_color {
+                                    e.color(accent_color);
+                                }
+                                e
+                            });
+                            m
+                        })
+                        .await
+                        .unwrap();
+                }
             }
         }
     } else if invalid_types {