diff --git a/Cargo.lock b/Cargo.lock
index f41ebe2..1c01368 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -133,6 +133,17 @@ dependencies = [
  "powerfmt",
 ]
 
+[[package]]
+name = "derive_utils"
+version = "0.14.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "61bb5a1014ce6dfc2a378578509abe775a5aa06bff584a547555d9efdb81b926"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "dirs-next"
 version = "2.0.0"
@@ -215,6 +226,15 @@ dependencies = [
  "hashbrown",
 ]
 
+[[package]]
+name = "io-enum"
+version = "1.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "53b53d712d99a73eec59ee5e4fe6057f8052142d38eeafbbffcb06b36d738a6e"
+dependencies = [
+ "derive_utils",
+]
+
 [[package]]
 name = "is-terminal"
 version = "0.4.12"
@@ -335,6 +355,7 @@ version = "0.1.0"
 dependencies = [
  "bitflags",
  "clap",
+ "io-enum",
  "rio_api",
  "rio_turtle",
  "serde",
diff --git a/Cargo.toml b/Cargo.toml
index 6eda731..33b985f 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -17,5 +17,6 @@ clap = { version = "4.5.7", features = ["derive"] }
 rio_turtle = "0.8.4"
 rio_api = "0.8.4"
 bitflags = "2.5.0"
+io-enum = "1.1.3"
 serde_yml = "0.0.10"
 tempfile = "3.10.1"
diff --git a/src/io.rs b/src/io.rs
index 941100f..3983da1 100644
--- a/src/io.rs
+++ b/src/io.rs
@@ -4,23 +4,37 @@ use serde_yml;
 use std::{
     boxed::Box,
     fs::File,
-    io::{stdin, stdout, BufRead, BufReader, BufWriter, Write},
+    io::{self, stdin, stdout, BufRead, BufReader, BufWriter, Write},
     path::Path,
 };
 
-/// Get a reader based on input path, either from stdin or a file.
-pub fn get_reader(path: &Path) -> Box<dyn BufRead> {
+use io_enum::{BufRead, Read, Write};
+
+#[derive(Read, BufRead)]
+pub enum Reader {
+    Stdio(BufReader<io::Stdin>),
+    File(BufReader<File>),
+}
+
+#[derive(Write)]
+pub enum Writer {
+    Stdio(BufWriter<io::Stdout>),
+    File(BufWriter<File>),
+}
+
+// Get a reader based on input path, either from stdin or a file.
+pub fn get_reader(path: &Path) -> Reader {
     return match path.to_str().unwrap() {
-        "-" => Box::new(BufReader::new(stdin())),
-        _ => Box::new(BufReader::new(File::open(&path).unwrap())),
+        "-" => Reader::Stdio(BufReader::new(stdin())),
+        path => Reader::File(BufReader::new(File::open(path).unwrap())),
     };
 }
 
-/// Get a writer based on input path, either to stdout or a file.
-pub fn get_writer(path: &Path) -> Box<dyn Write> {
+// Get a writer based on input path, either to stdout or a file.
+pub fn get_writer(path: &Path) -> Writer {
     return match path.to_str().unwrap() {
-        "-" => Box::new(BufWriter::new(stdout())),
-        path => Box::new(BufWriter::new(File::create(path).unwrap())),
+        "-" => Writer::Stdio(BufWriter::new(stdout())),
+        path => Writer::File(BufWriter::new(File::create(path).unwrap())),
     };
 }
 
diff --git a/src/main.rs b/src/main.rs
index a24b009..023439e 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -86,6 +86,7 @@ fn main() {
         Subcommands::Pseudo(args) => {
             info!(log, "Args: {:?}", args);
             pseudonymize_graph(&log, &args.input, &args.config, &args.output, &args.index)
+
         }
     }
 }
diff --git a/src/pass_first.rs b/src/pass_first.rs
index c71e1b1..fb378e2 100644
--- a/src/pass_first.rs
+++ b/src/pass_first.rs
@@ -1,6 +1,10 @@
-use rio_api::{model::Triple, parser::TriplesParser};
+use std::path::Path;
+use std::io::{BufRead, BufReader, stdin, Write};
+use rio_api::{
+    parser::TriplesParser,
+    model::Triple,
+};
 use rio_turtle::TurtleError;
-use std::{io::Write, path::Path};
 
 use crate::io;
 
diff --git a/src/pass_second.rs b/src/pass_second.rs
index 54afdbd..6d366c2 100644
--- a/src/pass_second.rs
+++ b/src/pass_second.rs
@@ -1,9 +1,7 @@
 use rio_api::{model::Triple, parser::TriplesParser};
 use rio_turtle::TurtleError;
 use std::{
-    collections::HashMap,
-    io::{BufRead, Write},
-    path::Path,
+    collections::HashMap, io::{BufRead, Write}, path::Path
 };
 
 use crate::{
@@ -14,7 +12,7 @@ use crate::{
 };
 
 fn mask_triple(triple: &Triple) -> TripleMask {
-    return TripleMask::SUBJECT;
+    return TripleMask::SUBJECT
 }
 
 // mask and encode input triple