diff --git a/proxmox-api-macro/src/api.rs b/proxmox-api-macro/src/api.rs
index 5f0acb6b..4fa2365c 100644
--- a/proxmox-api-macro/src/api.rs
+++ b/proxmox-api-macro/src/api.rs
@@ -336,19 +336,28 @@ impl SchemaItem {
 #[derive(Default)]
 /// Contains a sorted list of properties:
 pub struct SchemaObject {
-    properties: Vec<(FieldName, bool, Schema)>,
+    properties_: Vec<(FieldName, bool, Schema)>,
 }
 
 impl SchemaObject {
     pub fn new() -> Self {
         Self {
-            properties: Vec::new(),
+            properties_: Vec::new(),
         }
     }
 
+    #[inline]
+    fn properties_mut(&mut self) -> &mut [(FieldName, bool, Schema)] {
+        &mut self.properties_
+    }
+
+    fn sort_properties(&mut self) {
+        self.properties_.sort_by(|a, b| (a.0).cmp(&b.0));
+    }
+
     fn try_extract_from(obj: &mut JSONObject) -> Result<Self, syn::Error> {
-        Ok(Self {
-            properties: obj
+        let mut this = Self {
+            properties_: obj
                 .remove_required_element("properties")?
                 .into_object("object field definition")?
                 .into_iter()
@@ -371,17 +380,14 @@ impl SchemaObject {
 
                         Ok(properties)
                     },
-                )
-                // This must be kept sorted!
-                .map(|mut properties| {
-                    properties.sort_by(|a, b| (a.0).cmp(&b.0));
-                    properties
-                })?,
-        })
+                )?,
+        };
+        this.sort_properties();
+        Ok(this)
     }
 
     fn to_schema_inner(&self, ts: &mut TokenStream) -> Result<(), Error> {
-        for element in self.properties.iter() {
+        for element in self.properties_.iter() {
             let key = element.0.as_str();
             let optional = element.1;
             let mut schema = TokenStream::new();
@@ -393,23 +399,28 @@ impl SchemaObject {
 
     fn find_property_by_ident(&self, key: &str) -> Option<&(FieldName, bool, Schema)> {
         match self
-            .properties
+            .properties_
             .binary_search_by(|p| p.0.as_ident_str().cmp(key))
         {
-            Ok(idx) => Some(&self.properties[idx]),
+            Ok(idx) => Some(&self.properties_[idx]),
             Err(_) => None,
         }
     }
 
     fn find_property_by_ident_mut(&mut self, key: &str) -> Option<&mut (FieldName, bool, Schema)> {
         match self
-            .properties
+            .properties_
             .binary_search_by(|p| p.0.as_ident_str().cmp(key))
         {
-            Ok(idx) => Some(&mut self.properties[idx]),
+            Ok(idx) => Some(&mut self.properties_[idx]),
             Err(_) => None,
         }
     }
+
+    fn extend_properties(&mut self, new_fields: Vec<(FieldName, bool, Schema)>) {
+        self.properties_.extend(new_fields);
+        self.sort_properties();
+    }
 }
 
 pub struct SchemaArray {
diff --git a/proxmox-api-macro/src/api/structs.rs b/proxmox-api-macro/src/api/structs.rs
index c8926dc8..18e79e99 100644
--- a/proxmox-api-macro/src/api/structs.rs
+++ b/proxmox-api-macro/src/api/structs.rs
@@ -73,7 +73,7 @@ fn handle_regular_struct(
     // We also keep a reference to the SchemaObject around since we derive missing fields
     // automatically.
     if let api::SchemaItem::Object(ref mut obj) = &mut schema.item {
-        for field in &mut obj.properties {
+        for field in obj.properties_mut() {
             schema_fields.insert(field.0.as_str().to_string(), field);
         }
     } else {
@@ -140,7 +140,7 @@ fn handle_regular_struct(
 
     // add the fields we derived:
     if let api::SchemaItem::Object(ref mut obj) = &mut schema.item {
-        obj.properties.extend(new_fields);
+        obj.extend_properties(new_fields);
     } else {
         unreachable!();
     }
diff --git a/proxmox-api-macro/tests/types.rs b/proxmox-api-macro/tests/types.rs
index efa7a814..8c8b5ddf 100644
--- a/proxmox-api-macro/tests/types.rs
+++ b/proxmox-api-macro/tests/types.rs
@@ -43,11 +43,6 @@ fn test_struct() {
         &::proxmox::api::schema::ObjectSchema::new(
             "An example of a simple struct type.",
             &[
-                (
-                    "test_string",
-                    false,
-                    &::proxmox::api::schema::StringSchema::new("A test string.").schema(),
-                ),
                 (
                     "another",
                     true,
@@ -56,6 +51,11 @@ fn test_struct() {
                     )
                     .schema(),
                 ),
+                (
+                    "test_string",
+                    false,
+                    &::proxmox::api::schema::StringSchema::new("A test string.").schema(),
+                ),
             ],
         )
         .schema();
@@ -82,11 +82,6 @@ fn renamed_struct() {
         &::proxmox::api::schema::ObjectSchema::new(
             "An example of a struct with renamed fields.",
             &[
-                (
-                    "test-string",
-                    false,
-                    &::proxmox::api::schema::StringSchema::new("A test string.").schema(),
-                ),
                 (
                     "SomeOther",
                     true,
@@ -95,6 +90,11 @@ fn renamed_struct() {
                     )
                     .schema(),
                 ),
+                (
+                    "test-string",
+                    false,
+                    &::proxmox::api::schema::StringSchema::new("A test string.").schema(),
+                ),
             ],
         )
         .schema();