diff --git a/src/command/config.rs b/src/command/config.rs
index c01cfb4..426bfdb 100644
--- a/src/command/config.rs
+++ b/src/command/config.rs
@@ -21,9 +21,9 @@ pub(crate) enum ConfigVersion {
 #[derive(thiserror::Error, Debug)]
 pub(crate) enum Error {
     #[error(transparent)]
-    Migrate(#[from] migrate::Error),
+    Migrate(#[from] migrate::ConfigMigrateError),
     #[error(transparent)]
-    Validate(#[from] validate::Error),
+    Validate(#[from] validate::ConfigValidateError),
 }
 
 pub(crate) fn run(command: Commands) -> Result<(), Error> {
diff --git a/src/command/config/migrate.rs b/src/command/config/migrate.rs
index f80e1ee..680fc49 100644
--- a/src/command/config/migrate.rs
+++ b/src/command/config/migrate.rs
@@ -1,79 +1,16 @@
-use std::{
-    collections::HashMap,
-    env, fs,
-    io::{self, Read},
-};
-use yaml_rust::{Yaml, YamlLoader};
+mod v20240701;
 
-pub(super) fn run(version: super::ConfigVersion) -> Result<(), Error> {
-    match version {
-        super::ConfigVersion::V20240701 => migrate_20240701(),
-    }
-}
+use super::ConfigVersion;
 
 #[derive(thiserror::Error, Debug)]
-pub(crate) enum Error {
+pub(crate) enum ConfigMigrateError {
     #[error("failed to parse the old config file (.config/default.yml)")]
-    ReadOldConfig(#[from] ReadYamlConfigError),
+    ReadOldConfig(#[from] v20240701::ReadYamlConfigError),
 }
 
-#[derive(thiserror::Error, Debug)]
-pub(crate) enum ReadYamlConfigError {
-    #[error(transparent)]
-    ReadFile(#[from] io::Error),
-    #[error(transparent)]
-    Yaml(#[from] yaml_rust::ScanError),
-    #[error("invalid config file ({0})")]
-    InvalidConfig(String),
-}
-
-fn read_default_yml() -> Result<HashMap<String, Yaml>, ReadYamlConfigError> {
-    let cwd = env::current_dir()?;
-    let mut default_yml = fs::File::open(cwd.join(".config/default.yml"))?;
-
-    let mut buffer = String::new();
-    default_yml.read_to_string(&mut buffer)?;
-
-    let content = YamlLoader::load_from_str(&buffer)?;
-
-    if content.is_empty() {
-        return Err(ReadYamlConfigError::InvalidConfig(
-            "file is empty".to_string(),
-        ));
-    }
-    if content.len() > 2 || content[0].is_array() {
-        return Err(ReadYamlConfigError::InvalidConfig(
-            "top-level should not be an array".to_string(),
-        ));
-    }
-
-    let content = content[0]
-        .clone()
-        .into_hash()
-        .ok_or(ReadYamlConfigError::InvalidConfig(
-            "invalid format".to_string(),
-        ))?;
-
-    let mut res = HashMap::new();
-
-    for (key, val) in content {
-        let Some(key) = key.as_str() else {
-            return Err(ReadYamlConfigError::InvalidConfig(format!(
-                "non-string key found: {:?}",
-                key
-            )));
-        };
-        res.insert(key.to_owned(), val);
-    }
-
-    Ok(res)
-}
-
-fn migrate_20240701() -> Result<(), Error> {
-    let old_config = read_default_yml()?;
-
-    for (k, v) in old_config {
-        println!("{}:\n  {:?}", k, v);
+pub(super) fn run(version: ConfigVersion) -> Result<(), ConfigMigrateError> {
+    match version {
+        ConfigVersion::V20240701 => v20240701::run()?,
     }
 
     Ok(())
diff --git a/src/command/config/migrate/v20240701.rs b/src/command/config/migrate/v20240701.rs
new file mode 100644
index 0000000..b9b843d
--- /dev/null
+++ b/src/command/config/migrate/v20240701.rs
@@ -0,0 +1,64 @@
+use std::{collections::HashMap, env, fs, io::Read};
+use yaml_rust::{Yaml, YamlLoader};
+
+#[derive(thiserror::Error, Debug)]
+pub(crate) enum ReadYamlConfigError {
+    #[error(transparent)]
+    ReadFile(#[from] std::io::Error),
+    #[error(transparent)]
+    Yaml(#[from] yaml_rust::ScanError),
+    #[error("invalid config file ({0})")]
+    InvalidConfig(String),
+}
+
+fn read_default_yml() -> Result<HashMap<String, Yaml>, ReadYamlConfigError> {
+    let cwd = env::current_dir()?;
+    let mut default_yml = fs::File::open(cwd.join(".config/default.yml"))?;
+
+    let mut buffer = String::new();
+    default_yml.read_to_string(&mut buffer)?;
+
+    let content = YamlLoader::load_from_str(&buffer)?;
+
+    if content.is_empty() {
+        return Err(ReadYamlConfigError::InvalidConfig(
+            "file is empty".to_string(),
+        ));
+    }
+    if content.len() > 2 || content[0].is_array() {
+        return Err(ReadYamlConfigError::InvalidConfig(
+            "top-level should not be an array".to_string(),
+        ));
+    }
+
+    let content = content[0]
+        .clone()
+        .into_hash()
+        .ok_or(ReadYamlConfigError::InvalidConfig(
+            "invalid format".to_string(),
+        ))?;
+
+    let mut res = HashMap::new();
+
+    for (key, val) in content {
+        let Some(key) = key.as_str() else {
+            return Err(ReadYamlConfigError::InvalidConfig(format!(
+                "non-string key found: {:?}",
+                key
+            )));
+        };
+        res.insert(key.to_owned(), val);
+    }
+
+    Ok(res)
+}
+
+pub(super) fn run() -> Result<(), ReadYamlConfigError> {
+    let old_config = read_default_yml()?;
+
+    for (k, v) in old_config {
+        println!("{}:\n  {:?}", k, v);
+    }
+
+    Ok(())
+}
diff --git a/src/command/config/validate.rs b/src/command/config/validate.rs
index 5744af4..be96c6e 100644
--- a/src/command/config/validate.rs
+++ b/src/command/config/validate.rs
@@ -1,7 +1,7 @@
 #[derive(thiserror::Error, Debug)]
 #[error("failed to validate the config file")]
-pub(crate) struct Error;
+pub(crate) struct ConfigValidateError;
 
-pub(super) fn run() -> Result<(), Error> {
+pub(super) fn run() -> Result<(), ConfigValidateError> {
     unimplemented!()
 }
diff --git a/src/main.rs b/src/main.rs
index 021f452..fe9abd3 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -34,7 +34,7 @@ fn run() -> Result<(), command::Error> {
 fn main() {
     let res = run();
 
-    if let Err(err) = res {       
+    if let Err(err) = res {
         println!("An error occurred!");
         println!("      raw: {:?}", err);
         println!("  message: {}", err);