diff --git a/macro/src/gen/mod.rs b/macro/src/gen/mod.rs
index cbcfa63..5957788 100644
--- a/macro/src/gen/mod.rs
+++ b/macro/src/gen/mod.rs
@@ -30,9 +30,10 @@ fn gen_config_impl(input: &ir::Input) -> TokenStream {
         match f.kind {
             FieldKind::Nested { .. } => {
                 quote! {
-                    confique::Config::from_partial(partial.#field_name).map_err(|e| {
-                        confique::internal::prepend_missing_value_error(e, #path)
-                    })?
+                    confique::internal::map_err_prefix_path(
+                        confique::Config::from_partial(partial.#field_name),
+                        #path,
+                    )?
                 }
             }
             FieldKind::Leaf { kind: LeafKind::Optional { .. }, .. } => {
@@ -40,8 +41,7 @@ fn gen_config_impl(input: &ir::Input) -> TokenStream {
             }
             FieldKind::Leaf { kind: LeafKind::Required { .. }, .. } => {
                 quote! {
-                    partial.#field_name
-                        .ok_or(confique::internal::missing_value_error(#path.into()))?
+                    confique::internal::unwrap_or_missing_value_err(partial.#field_name, #path)?
                 }
             }
         }
diff --git a/src/internal.rs b/src/internal.rs
index 009d28e..1c5ca65 100644
--- a/src/internal.rs
+++ b/src/internal.rs
@@ -19,17 +19,21 @@ where
     src.into_deserializer()
 }
 
-pub fn missing_value_error(path: String) -> Error {
-    ErrorInner::MissingValue(path).into()
+pub fn unwrap_or_missing_value_err<T>(value: Option<T>, path: &str) -> Result<T, Error> {
+    match value {
+        Some(v) => Ok(v),
+        None => Err(ErrorInner::MissingValue(path.into()).into())
+    }
 }
 
-pub fn prepend_missing_value_error(e: Error, prefix: &str) -> Error {
-    match *e.inner {
-        ErrorInner::MissingValue(path) => {
+pub fn map_err_prefix_path<T>(res: Result<T, Error>, prefix: &str) -> Result<T, Error> {
+    res.map_err(|e| {
+        if let ErrorInner::MissingValue(path) = &*e.inner {
             ErrorInner::MissingValue(format!("{prefix}.{path}")).into()
+        } else {
+            e
         }
-        e => e.into(),
-    }
+    })
 }
 
 pub fn from_env<'de, T: serde::Deserialize<'de>>(