diff --git a/src/main.rs b/src/main.rs
index d53433f..ec68b55 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -48,6 +48,7 @@ struct Args {
     pub raw: bool,
 
     /// The roots to use for discovery.
+    #[clap(required = true)]
     pub roots: Vec<PathBuf>,
 }