diff --git a/src/bin/roundtrip.rs b/src/bin/roundtrip.rs
deleted file mode 100644
index e75d032..0000000
--- a/src/bin/roundtrip.rs
+++ /dev/null
@@ -1,13 +0,0 @@
-//! Roundtrip utility.
-
-use std::io::{Read, Write};
-use waffle::Module;
-
-fn main() {
-    let _ = env_logger::try_init();
-    let mut bytes = vec![];
-    std::io::stdin().read_to_end(&mut bytes).unwrap();
-    let module = Module::from_wasm_bytes(&bytes).unwrap();
-    let new_bytes = module.to_wasm_bytes();
-    std::io::stdout().write(&new_bytes[..]).unwrap();
-}
diff --git a/src/bin/waffle-util.rs b/src/bin/waffle-util.rs
index b6037ae..976da0a 100644
--- a/src/bin/waffle-util.rs
+++ b/src/bin/waffle-util.rs
@@ -23,6 +23,13 @@ enum Command {
         #[structopt(help = "Wasm file to parse")]
         wasm: PathBuf,
     },
+    #[structopt(name = "roundtrip", about = "Round-trip Wasm through IR")]
+    RoundTrip {
+        #[structopt(help = "Wasm file to parse", short = "i")]
+        input: PathBuf,
+        #[structopt(help = "Wasm file to produce", short = "o")]
+        output: PathBuf,
+    },
 }
 
 fn main() -> Result<()> {
@@ -41,6 +48,13 @@ fn main() -> Result<()> {
             let module = Module::from_wasm_bytes(&bytes[..])?;
             println!("{:?}", module);
         }
+        Command::RoundTrip { input, output } => {
+            let bytes = std::fs::read(input)?;
+            debug!("Loaded {} bytes of Wasm data", bytes.len());
+            let module = Module::from_wasm_bytes(&bytes[..])?;
+            let produced = module.to_wasm_bytes();
+            std::fs::write(output, &produced[..])?;
+        }
     }
 
     Ok(())