diff --git a/src/config.rs b/src/config.rs
index 8312aab3..db4e8ca4 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -15,6 +15,10 @@ lazy_static::lazy_static! {
         RwLock::new(HashMap::new());
 }
 
+pub fn config_file_name() -> &'static str {
+    CONFIG_FILE_NAME
+}
+
 #[derive(PartialEq, Eq, Debug, serde::Deserialize)]
 #[serde(rename_all = "kebab-case")]
 pub(crate) struct Config {
diff --git a/src/handlers.rs b/src/handlers.rs
index 7e4a04f9..acb18c15 100644
--- a/src/handlers.rs
+++ b/src/handlers.rs
@@ -133,6 +133,29 @@ macro_rules! issue_handlers {
             config: &Arc<Config>,
             errors: &mut Vec<HandlerError>,
         ) {
+            if event.issue.is_pr() {
+                if let Ok(Some(diff)) = event.issue.diff(&ctx.github).await {
+                    if let Some(source) = &event.issue.head {
+                    if diff.contains(config::config_file_name()) {
+                        if let Some(Some(triagebot_toml)) = ctx.github
+                            .raw_file(&source.repo.full_name, &source.git_ref, crate::config::config_file_name())
+                            .await.ok() {
+                                match toml::from_slice::<crate::handlers::Config>(&triagebot_toml) {
+                                    Ok(_) => {},
+                                    Err(err) => {
+                                        errors.push(HandlerError::Message(format!(
+                                            "The triagebot.toml file is not a valid config file.\n\
+                                            Error: {}",
+                                            err
+                                        )));
+                                    }
+                                }
+                            }
+                    }
+                }
+                }
+            }
+
             $(
             match $name::parse_input(ctx, event, config.$name.as_ref()).await {
                 Err(err) => errors.push(HandlerError::Message(err)),