diff --git a/src/main.rs b/src/main.rs
index 14ba9af..11049f5 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -26,6 +26,7 @@ extern crate rand;
 
 use structopt::StructOpt;
 use serde::{Serialize,Deserialize};
+use serde_json::json;
 
 // define the commandline parameters
 #[derive(StructOpt)]
@@ -130,7 +131,9 @@ fn main()
 	else
 	{
 		// export data to JSON format
-		let out_json = serde_json::to_string(&prisoners).unwrap();
+		let out_json = json!({
+				"prisoners": prisoners
+			});
 		println!("{}", out_json);
 	}
 }