diff --git a/src/lib.rs b/src/lib.rs
index 3f8e1fd..e51e517 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,35 +1,6 @@
 #[macro_use]
 extern crate justerror;
 
-use argon2::{
-    password_hash::{rand_core::OsRng, PasswordHash, PasswordHasher, PasswordVerifier, SaltString},
-    Argon2,
-};
-use uuid::Uuid;
-
 pub mod db;
 pub mod handlers;
-
-fn create_user(username: &str, password: &[u8]) -> Result<Uuid, CreateUserError> {
-    // Argon2 with default params (Argon2id v19)
-    let argon2 = Argon2::default();
-
-    let salt = SaltString::generate(&mut OsRng);
-    let password_hash = argon2
-        .hash_password(password, &salt)
-        .unwrap() // safe to unwrap, we know the salt is valid
-        .to_string();
-
-    todo!()
-}
-
-#[Error(desc = "Could not create user.")]
-#[non_exhaustive]
-pub struct CreateUserError(#[from] CreateUserErrorKind);
-
-#[Error]
-#[non_exhaustive]
-pub enum CreateUserErrorKind {
-    AlreadyExists,
-    Unknown,
-}
+pub mod users;
diff --git a/src/users.rs b/src/users.rs
new file mode 100644
index 0000000..5dbd329
--- /dev/null
+++ b/src/users.rs
@@ -0,0 +1,31 @@
+use argon2::{
+    password_hash::{rand_core::OsRng, PasswordHash, PasswordHasher, PasswordVerifier, SaltString},
+    Argon2,
+};
+use uuid::Uuid;
+
+fn create_user(username: &str, password: &[u8]) -> Result<Uuid, CreateUserError> {
+    // Argon2 with default params (Argon2id v19)
+    let argon2 = Argon2::default();
+
+    let salt = SaltString::generate(&mut OsRng);
+    let password_hash = argon2
+        .hash_password(password, &salt)
+        .unwrap() // safe to unwrap, we know the salt is valid
+        .to_string();
+
+    todo!()
+}
+
+#[Error(desc = "Could not create user.")]
+#[non_exhaustive]
+pub struct CreateUserError(#[from] CreateUserErrorKind);
+
+#[Error]
+#[non_exhaustive]
+pub enum CreateUserErrorKind {
+    AlreadyExists,
+    PasswordMismatch,
+    MissingFields,
+    Unknown,
+}