diff --git a/bipc/src/main.rs b/bipc/src/main.rs
index 6489fc1..ffa0b95 100644
--- a/bipc/src/main.rs
+++ b/bipc/src/main.rs
@@ -3,7 +3,7 @@ use clap::Parser;
 #[derive(Parser)]
 struct Args {
     /// Path for converted output
-    #[arg(short, long, default_value = "out")]
+    #[arg(short, long, default_value = "out.bp")]
     outfile: String,
 
     /// Path to bip file