diff --git a/src/bin/bitsy-merge.rs b/src/bin/bitsy-merge.rs
index e7832f2..79df5d2 100644
--- a/src/bin/bitsy-merge.rs
+++ b/src/bin/bitsy-merge.rs
@@ -2,25 +2,19 @@ extern crate bitsy_parser;
 use bitsy_parser::game::Game;
 use std::{env, fs};
 
+const SYNTAX_ERROR: &str = "No main game specified. Usage: `bitsy-merge main.bitsy additional.bitsy output.bitsy`";
+
 fn main() {
-    let game_a = env::args()
-        .nth(1)
-        .expect("No main game specified. Usage: `bitsy-merge main.bitsy additional.bitsy output.bitsy`");
-
+    let game_a = env::args().nth(1).expect(SYNTAX_ERROR);
+    let game_b = env::args().nth(2).expect(SYNTAX_ERROR);
+    let output = env::args().nth(3).expect(SYNTAX_ERROR);
     // todo allow numerous additional games
-    let game_b = env::args()
-        .nth(2)
-        .expect("No additional game specified. Usage: `bitsy-merge main.bitsy additional.bitsy output.bitsy`");
-
-    let outfile = env::args()
-        .nth(3)
-        .expect("No output file specified. Usage: `bitsy-merge main.bitsy additional.bitsy output.bitsy`");
 
     let mut game_a = Game::from(fs::read_to_string(game_a).unwrap()).unwrap();
     let     game_b = Game::from(fs::read_to_string(game_b).unwrap()).unwrap();
 
     game_a.merge(game_b);
 
-    fs::write(outfile, game_a.to_string())
+    fs::write(output, game_a.to_string())
         .expect("Failed to write output file");
 }