diff --git a/crates/cli/src/commands/codegen.rs b/crates/cli/src/commands/codegen.rs
index b49cbce..486dbc1 100644
--- a/crates/cli/src/commands/codegen.rs
+++ b/crates/cli/src/commands/codegen.rs
@@ -148,7 +148,7 @@ impl GetSchemaCommand for Opts {
 impl Opts {
     pub fn run(
         &self,
-        schema: &mut Schema,
+        schema: &Schema,
         discovery: &Discovery,
         storage: &SchemaStorage,
     ) -> Result<(), Error> {
@@ -241,7 +241,7 @@ impl Opts {
 }
 
 pub fn execute(opts: Opts, client: &Client) -> Result<(), Error> {
-    let mut schema = opts.get_schema(client)?;
+    let schema = opts.get_schema(client)?;
     let storage = &SchemaStorage::new(&schema, client);
     let discovery = Discovery::default();
 
@@ -249,12 +249,12 @@ pub fn execute(opts: Opts, client: &Client) -> Result<(), Error> {
         Command::JsonSchema(o) => {
             o.verbose.start()?;
 
-            opts.run(&mut schema, &discovery, storage)
+            opts.run(&schema, &discovery, storage)
         }
         Command::Openapi(o) => {
             o.verbose.start()?;
 
-            opts.run(&mut schema, &discovery, storage)
+            opts.run(&schema, &discovery, storage)
         }
     }
 }
diff --git a/crates/cli/src/commands/validate.rs b/crates/cli/src/commands/validate.rs
index a027876..bcb2559 100644
--- a/crates/cli/src/commands/validate.rs
+++ b/crates/cli/src/commands/validate.rs
@@ -77,7 +77,7 @@ impl GetSchemaCommand for Opts {
 }
 
 impl Opts {
-    pub fn run(&self, schema: &mut Schema) -> Result<(), Error> {
+    pub fn run(&self, schema: &Schema) -> Result<(), Error> {
         match &self.command {
             Command::Openapi(_) => validate::validate_openapi(schema).map_err(Error::Schematools),
             Command::JsonSchema(_) => {
@@ -108,16 +108,16 @@ impl Opts {
 }
 
 pub fn execute(opts: Opts, client: &Client) -> Result<(), Error> {
-    let mut schema = opts.get_schema(client)?;
+    let schema = opts.get_schema(client)?;
 
     match &opts.command {
         Command::Openapi(o) => {
             o.verbose.start()?;
-            opts.run(&mut schema)
+            opts.run(&schema)
         }
         Command::JsonSchema(o) => {
             o.verbose.start()?;
-            opts.run(&mut schema)
+            opts.run(&schema)
         }
     }
 }
diff --git a/crates/schematools/src/codegen/jsonschema/oneof/extractor.rs b/crates/schematools/src/codegen/jsonschema/oneof/extractor.rs
index d7b1a9e..82776ff 100644
--- a/crates/schematools/src/codegen/jsonschema/oneof/extractor.rs
+++ b/crates/schematools/src/codegen/jsonschema/oneof/extractor.rs
@@ -30,10 +30,17 @@ pub trait Extractor {
 #[derive(Serialize)]
 pub struct DiscriminatorMeta {
     pub property: String,
-    pub value: String,
+    pub value: DiscriminatorValue,
     pub properties: Option<usize>,
 }
 
+#[derive(Serialize)]
+#[serde(rename_all = "camelCase")]
+pub enum DiscriminatorValue {
+    Model(String),
+    Simple(FlatModel),
+}
+
 pub struct Simple {
     properties: Vec<SimpleProperty>,
 }
@@ -115,8 +122,8 @@ impl Simple {
                         value: f
                             .model
                             .as_ref()
-                            .and_then(|m| m.name.clone())
-                            .unwrap_or(f.name.clone().unwrap()),
+                            .and_then(|m| m.name.clone().map(DiscriminatorValue::Model))
+                            .unwrap_or(DiscriminatorValue::Simple(f.clone())),
                         properties: Some(object.properties.len()),
                     }
                 })
@@ -131,7 +138,11 @@ impl Simple {
 
                         DiscriminatorMeta {
                             property: f.name.clone().unwrap(),
-                            value: f.model.as_ref().and_then(|m| m.name.clone()).unwrap(),
+                            value: f
+                                .model
+                                .as_ref()
+                                .and_then(|m| m.name.clone().map(DiscriminatorValue::Model))
+                                .unwrap_or(DiscriminatorValue::Simple(f.clone())),
                             properties: Some(object.properties.len() - 1),
                         }
                     })
@@ -213,7 +224,7 @@ impl Extractor for Discriminator {
                     DISCRIMINATOR_META.to_owned(),
                     serde_json::to_value(DiscriminatorMeta {
                         property: self.property.clone(),
-                        value: value.clone(),
+                        value: DiscriminatorValue::Model(value.clone()),
                         properties,
                     })
                     .unwrap(),
diff --git a/crates/schematools/src/codegen/jsonschema/oneof/mod.rs b/crates/schematools/src/codegen/jsonschema/oneof/mod.rs
index 8988d4b..3922b69 100644
--- a/crates/schematools/src/codegen/jsonschema/oneof/mod.rs
+++ b/crates/schematools/src/codegen/jsonschema/oneof/mod.rs
@@ -176,7 +176,19 @@ mod tests {
                                 "_discriminator".to_string(),
                                 json!({
                                     "property": "some",
-                                    "value": "some",
+                                    "value": {
+                                        "simple": {
+                                            "name": "some",
+                                            "type": "string",
+                                            "model": null,
+                                            "required": true,
+                                            "nullable": false,
+                                            "validation": null,
+                                            "x": {},
+                                            "description": null,
+                                            "default": null
+                                        }
+                                    },
                                     "properties": 1
                                 })
                             )]
@@ -202,7 +214,19 @@ mod tests {
                                 "_discriminator".to_string(),
                                 json!({
                                     "property": "testing",
-                                    "value": "testing",
+                                    "value": {
+                                        "simple": {
+                                            "name": "testing",
+                                            "type": "number",
+                                            "model": null,
+                                            "required": true,
+                                            "nullable": false,
+                                            "validation": null,
+                                            "x": {},
+                                            "description": null,
+                                            "default": null
+                                        }
+                                    },
                                     "properties": 1
                                 })
                             )]
@@ -263,7 +287,7 @@ mod tests {
                                 "_discriminator".to_string(),
                                 json!({
                                     "property": "type",
-                                    "value": "value1",
+                                    "value": {"model": "value1"},
                                     "properties": 1
                                 })
                             )]
@@ -289,7 +313,7 @@ mod tests {
                                 "_discriminator".to_string(),
                                 json!({
                                     "property": "type",
-                                    "value": "value2",
+                                    "value": {"model":"value2"},
                                     "properties": 1
                                 })
                             )]
diff --git a/crates/schematools/src/codegen/jsonschema/required.rs b/crates/schematools/src/codegen/jsonschema/required.rs
index d5e24fd..7488111 100644
--- a/crates/schematools/src/codegen/jsonschema/required.rs
+++ b/crates/schematools/src/codegen/jsonschema/required.rs
@@ -2,7 +2,7 @@ use crate::scope::SchemaScope;
 use serde_json::Map;
 use serde_json::Value;
 
-pub fn extract_required(data: &Map<String, Value>, scope: &mut SchemaScope) -> Vec<String> {
+pub fn extract_required(data: &Map<String, Value>, scope: &SchemaScope) -> Vec<String> {
     match data.get("required").unwrap_or(&serde_json::json!([])) {
         Value::Array(a) => a.iter().map(|v| v.as_str().unwrap().to_string()).collect(),
         _ => {
diff --git a/crates/schematools/src/codegen/jsonschema/types.rs b/crates/schematools/src/codegen/jsonschema/types.rs
index 4bf0e26..d195599 100644
--- a/crates/schematools/src/codegen/jsonschema/types.rs
+++ b/crates/schematools/src/codegen/jsonschema/types.rs
@@ -588,7 +588,7 @@ impl Default for Attributes {
 }
 
 impl AnyType {
-    pub fn model(schema: &Map<String, Value>, scope: &mut SchemaScope) -> Model {
+    pub fn model(schema: &Map<String, Value>, scope: &SchemaScope) -> Model {
         log::debug!("{}: {:?} may be invalid json schema", scope, schema);
 
         Model::new(ModelType::AnyType(Self {}))
diff --git a/crates/schematools/src/codegen/openapi/endpoint.rs b/crates/schematools/src/codegen/openapi/endpoint.rs
index 793a646..87ef6ad 100644
--- a/crates/schematools/src/codegen/openapi/endpoint.rs
+++ b/crates/schematools/src/codegen/openapi/endpoint.rs
@@ -40,7 +40,7 @@ pub fn extract_endpoints(
     path: &str,
     scope: &mut SchemaScope,
     mcontainer: &mut ModelContainer,
-    scontainer: &mut security::SecuritySchemes,
+    scontainer: &security::SecuritySchemes,
     resolver: &SchemaResolver,
     options: &JsonSchemaExtractOptions,
 ) -> Result<Vec<Endpoint>, Error> {
@@ -93,7 +93,7 @@ fn new_endpoint(
     method: &str,
     scope: &mut SchemaScope,
     mcontainer: &mut ModelContainer,
-    scontainer: &mut security::SecuritySchemes,
+    scontainer: &security::SecuritySchemes,
     resolver: &SchemaResolver,
     options: &JsonSchemaExtractOptions,
 ) -> Result<Endpoint, Error> {
diff --git a/crates/schematools/src/codegen/openapi/mod.rs b/crates/schematools/src/codegen/openapi/mod.rs
index 5c2c622..153b32b 100644
--- a/crates/schematools/src/codegen/openapi/mod.rs
+++ b/crates/schematools/src/codegen/openapi/mod.rs
@@ -154,7 +154,7 @@ pub fn extract(
     tools::each_node(root, &mut scope, "path:security", |node, _parts, scope| {
         scope.glue("security");
 
-        let schemes = security::extract_defaults(node, scope, &mut scontainer)?;
+        let schemes = security::extract_defaults(node, scope, &scontainer)?;
         for scheme in schemes {
             scontainer.add_default(scheme);
         }
@@ -247,7 +247,7 @@ pub fn extract(
                     path,
                     scope,
                     &mut mcontainer,
-                    &mut scontainer,
+                    &scontainer,
                     resolver,
                     options,
                 )?;
diff --git a/crates/schematools/src/codegen/openapi/security.rs b/crates/schematools/src/codegen/openapi/security.rs
index 70195af..d2b8b5c 100644
--- a/crates/schematools/src/codegen/openapi/security.rs
+++ b/crates/schematools/src/codegen/openapi/security.rs
@@ -87,7 +87,7 @@ pub fn new_scheme(
 pub fn extract_defaults(
     node: &Value,
     scope: &mut SchemaScope,
-    scontainer: &mut SecuritySchemes,
+    scontainer: &SecuritySchemes,
 ) -> Result<Vec<SecurityScheme>, Error> {
     match node {
         Value::Array(scheme_names) => {
@@ -113,7 +113,7 @@ pub fn extract_defaults(
 
 pub fn extract_default(
     node: &Value,
-    scontainer: &mut SecuritySchemes,
+    scontainer: &SecuritySchemes,
 ) -> Result<Option<SecurityScheme>, Error> {
     match node {
         Value::Object(data) => {
diff --git a/crates/schematools/src/process/dereference.rs b/crates/schematools/src/process/dereference.rs
index 88c7953..9a7d617 100644
--- a/crates/schematools/src/process/dereference.rs
+++ b/crates/schematools/src/process/dereference.rs
@@ -212,7 +212,7 @@ fn process_node(
     }
 }
 
-fn process_discriminator(root: &mut Value, ctx: &mut DereferencerContext) {
+fn process_discriminator(root: &mut Value, ctx: &DereferencerContext) {
     log::debug!("{}: processing discriminator", ctx.scope);
 
     if let Value::Object(ref mut map) = root {