--- a/helix-view/src/document.rs
+++ b/helix-view/src/document.rs
@@ -762,6 +762,7 @@ pub fn format(&self) -> Option<BoxFuture<'static, Result<Transaction, FormatterE
             let text = self.text().clone();
             let mut process = tokio::process::Command::new(&fmt_cmd);
             process
+                .env("HX_FILE", self.path()?.to_str().unwrap_or(""))
                 .args(fmt_args)
                 .stdin(Stdio::piped())
                 .stdout(Stdio::piped())