diff --git a/src/main.rs b/src/main.rs
index f720d4c..a3c6c85 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -325,6 +325,7 @@ async fn main () -> Result<()> {
              .value_name("APP")
              .num_args(1)
              .value_parser(["mp4decrypt", "shaka"])
+             .default_value("shaka")
              .help("Application to use to decrypt encrypted media streams (either mp4decrypt or shaka)."))
         .arg(Arg::new("save-fragments")
              .long("save-fragments")