diff --git a/src/env.rs b/src/env/mod.rs
similarity index 55%
rename from src/env.rs
rename to src/env/mod.rs
index 4580661..e917aa3 100644
--- a/src/env.rs
+++ b/src/env/mod.rs
@@ -5,6 +5,9 @@ use std::fmt;
 use serde::de::IntoDeserializer;
 
 
+pub mod parse;
+
+
 /// Error type only for deserialization of env values.
 ///
 /// Semantically private, only public as it's used in the API of the `internal`
@@ -132,97 +135,4 @@ impl<'de> serde::Deserializer<'de> for Deserializer {
 
 
 #[cfg(test)]
-mod tests {
-    use super::*;
-
-    fn de<'de, T: serde::Deserialize<'de>>(v: &'static str) -> Result<T, DeError> {
-        T::deserialize(Deserializer { value: v.into() })
-    }
-
-
-    #[test]
-    fn boolean() {
-        assert_eq!(de("1"), Ok(true));
-        assert_eq!(de("true "), Ok(true));
-        assert_eq!(de("  TRUE"), Ok(true));
-        assert_eq!(de("0  "), Ok(false));
-        assert_eq!(de(" false"), Ok(false));
-        assert_eq!(de("FALSE "), Ok(false));
-    }
-
-    #[test]
-    fn ints() {
-        assert_eq!(de("0"), Ok(0u8));
-        assert_eq!(de("-1 "), Ok(-1i8));
-        assert_eq!(de(" 27"), Ok(27u16));
-        assert_eq!(de("-27"), Ok(-27i16));
-        assert_eq!(de("   4301"), Ok(4301u32));
-        assert_eq!(de(" -123456"), Ok(-123456i32));
-        assert_eq!(de(" 986543210    "), Ok(986543210u64));
-        assert_eq!(de("-986543210"), Ok(-986543210i64));
-    }
-
-    #[test]
-    fn floats() {
-        assert_eq!(de("3.1415"), Ok(3.1415f32));
-        assert_eq!(de("-123.456"), Ok(-123.456f64));
-    }
-}
-
-/// Functions for the `#[config(parse_env = ...)]` attribute.
-pub mod parse {
-    use std::str::FromStr;
-
-    /// Splits the environment variable by separator `SEP`, parses each element
-    /// with [`FromStr`] and collects everything via [`FromIterator`].
-    ///
-    /// To avoid having to specify the separator via `::<>` syntax, see the
-    /// other functions in this module.
-    ///
-    /// [`FromStr`]: std::str::FromStr
-    /// [`FromIterator`]: std::iter::FromIterator
-    ///
-    ///
-    /// # Example
-    ///
-    /// ```
-    /// use confique::Config;
-    ///
-    /// #[derive(Debug, confique::Config)]
-    /// struct Conf {
-    ///     #[config(env = "PORTS", parse_env = confique::env::parse::list_by_sep::<',', _, _>)]
-    ///     ports: Vec<u16>,
-    /// }
-    ///
-    /// std::env::set_var("PORTS", "8080,8000,8888");
-    /// let conf = Conf::builder().env().load()?;
-    /// assert_eq!(conf.ports, vec![8080, 8000, 8888]);
-    /// # Ok::<_, confique::Error>(())
-    /// ```
-    pub fn list_by_sep<const SEP: char, T, C>(input: &str) -> Result<C, <T as FromStr>::Err>
-    where
-        T: FromStr,
-        C: FromIterator<T>,
-    {
-        input.split(SEP).map(T::from_str).collect()
-    }
-
-
-    macro_rules! specify_fn_wrapper {
-        ($fn_name:ident, $sep:literal) => {
-            #[doc = concat!("Like [`list_by_sep`] with `", $sep, "` separator.")]
-            pub fn $fn_name<T, C>(input: &str) -> Result<C, <T as FromStr>::Err>
-            where
-                T: FromStr,
-                C: FromIterator<T>,
-            {
-                list_by_sep::<$sep, _, _>(input)
-            }
-        }
-    }
-
-    specify_fn_wrapper!(list_by_comma, ',');
-    specify_fn_wrapper!(list_by_semicolon, ';');
-    specify_fn_wrapper!(list_by_colon, ':');
-    specify_fn_wrapper!(list_by_space, ' ');
-}
+mod tests;
diff --git a/src/env/parse.rs b/src/env/parse.rs
new file mode 100644
index 0000000..aa81359
--- /dev/null
+++ b/src/env/parse.rs
@@ -0,0 +1,56 @@
+//! Functions for the `#[config(parse_env = ...)]` attribute.
+
+use std::str::FromStr;
+
+/// Splits the environment variable by separator `SEP`, parses each element
+/// with [`FromStr`] and collects everything via [`FromIterator`].
+///
+/// To avoid having to specify the separator via `::<>` syntax, see the
+/// other functions in this module.
+///
+/// [`FromStr`]: std::str::FromStr
+/// [`FromIterator`]: std::iter::FromIterator
+///
+///
+/// # Example
+///
+/// ```
+/// use confique::Config;
+///
+/// #[derive(Debug, confique::Config)]
+/// struct Conf {
+///     #[config(env = "PORTS", parse_env = confique::env::parse::list_by_sep::<',', _, _>)]
+///     ports: Vec<u16>,
+/// }
+///
+/// std::env::set_var("PORTS", "8080,8000,8888");
+/// let conf = Conf::builder().env().load()?;
+/// assert_eq!(conf.ports, vec![8080, 8000, 8888]);
+/// # Ok::<_, confique::Error>(())
+/// ```
+pub fn list_by_sep<const SEP: char, T, C>(input: &str) -> Result<C, <T as FromStr>::Err>
+where
+    T: FromStr,
+    C: FromIterator<T>,
+{
+    input.split(SEP).map(T::from_str).collect()
+}
+
+
+macro_rules! specify_fn_wrapper {
+    ($fn_name:ident, $sep:literal) => {
+        #[doc = concat!("Like [`list_by_sep`] with `", $sep, "` separator.")]
+        pub fn $fn_name<T, C>(input: &str) -> Result<C, <T as FromStr>::Err>
+        where
+            T: FromStr,
+            C: FromIterator<T>,
+        {
+            list_by_sep::<$sep, _, _>(input)
+        }
+    }
+}
+
+specify_fn_wrapper!(list_by_comma, ',');
+specify_fn_wrapper!(list_by_semicolon, ';');
+specify_fn_wrapper!(list_by_colon, ':');
+specify_fn_wrapper!(list_by_space, ' ');
diff --git a/src/env/tests.rs b/src/env/tests.rs
new file mode 100644
index 0000000..7fdeb3e
--- /dev/null
+++ b/src/env/tests.rs
@@ -0,0 +1,34 @@
+use super::*;
+
+fn de<'de, T: serde::Deserialize<'de>>(v: &'static str) -> Result<T, DeError> {
+    T::deserialize(Deserializer { value: v.into() })
+}
+
+
+#[test]
+fn boolean() {
+    assert_eq!(de("1"), Ok(true));
+    assert_eq!(de("true "), Ok(true));
+    assert_eq!(de("  TRUE"), Ok(true));
+    assert_eq!(de("0  "), Ok(false));
+    assert_eq!(de(" false"), Ok(false));
+    assert_eq!(de("FALSE "), Ok(false));
+}
+
+#[test]
+fn ints() {
+    assert_eq!(de("0"), Ok(0u8));
+    assert_eq!(de("-1 "), Ok(-1i8));
+    assert_eq!(de(" 27"), Ok(27u16));
+    assert_eq!(de("-27"), Ok(-27i16));
+    assert_eq!(de("   4301"), Ok(4301u32));
+    assert_eq!(de(" -123456"), Ok(-123456i32));
+    assert_eq!(de(" 986543210    "), Ok(986543210u64));
+    assert_eq!(de("-986543210"), Ok(-986543210i64));
+}
+
+#[test]
+fn floats() {
+    assert_eq!(de("3.1415"), Ok(3.1415f32));
+    assert_eq!(de("-123.456"), Ok(-123.456f64));
+}