diff --git a/Cargo.lock b/Cargo.lock
index f52d966..8ac7bcc 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1124,6 +1124,7 @@ dependencies = [
  "quote",
  "serde",
  "serde_json",
+ "serde_yaml",
  "syn 2.0.23",
  "tera",
  "tracing-ez",
@@ -1669,9 +1670,9 @@ dependencies = [
 
 [[package]]
 name = "serde_yaml"
-version = "0.9.22"
+version = "0.9.25"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "452e67b9c20c37fa79df53201dc03839651086ed9bbe92b3ca585ca9fdaa7d85"
+checksum = "1a49e178e4452f45cb61d0cd8cebc1b0fafd3e41929e996cef79aa3aca91f574"
 dependencies = [
  "indexmap 2.0.0",
  "itoa",
diff --git a/Cargo.toml b/Cargo.toml
index adb0db6..d9468e6 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,4 +1,5 @@
 [workspace]
+resolver = "2"
 members = [
     "libninja",
     "macro",
diff --git a/Justfile b/Justfile
index c314e3d..ff1683c 100644
--- a/Justfile
+++ b/Justfile
@@ -96,6 +96,7 @@ generate:
     cargo run -- gen --name $SERVICE --output-dir $REPO_DIR --generator $SOURCEGEN --github $REPO --version $VERSION $LIBRARY $SPEC
 
 test *ARGS:
+    cd core && cargo test -- "$@"
     cd libninja && cargo test -- "$@"
 alias t := test
 
diff --git a/core/Cargo.toml b/core/Cargo.toml
index d5b16a9..a74c8c2 100644
--- a/core/Cargo.toml
+++ b/core/Cargo.toml
@@ -20,3 +20,6 @@ syn = "2.0"
 ln-mir = { path = "../mir" }
 include_dir = "0.7.3"
 tera = "1.19.0"
+
+[dev-dependencies]
+serde_yaml = "0.9.25"
\ No newline at end of file
diff --git a/core/src/extractor/pet_tag.yaml b/core/src/extractor/pet_tag.yaml
new file mode 100644
index 0000000..7f19041
--- /dev/null
+++ b/core/src/extractor/pet_tag.yaml
@@ -0,0 +1,13 @@
+allOf:
+  - type: object
+    required:
+      - eye-color
+    properties:
+      eye-color:
+        type: string
+        enum:
+          - blue
+          - brown
+          - green
+      weight:
+        type: integer
\ No newline at end of file
diff --git a/core/src/extractor/record.rs b/core/src/extractor/record.rs
index 7bfb36d..f19b690 100644
--- a/core/src/extractor/record.rs
+++ b/core/src/extractor/record.rs
@@ -119,7 +119,10 @@ fn create_record_from_all_of(name: &str, all_of: &[ReferenceOr<Schema>], schema_
                 match item.properties() {
                     Some(props) => {
                         for (name, schema) in props {
-                            let field = create_field(schema, spec);
+                            let mut field = create_field(schema, spec);
+                            if !item.required(name) {
+                                field.optional = true;
+                            }
                             fields.insert(Name::new(name), field);
                         }
                     }
@@ -154,3 +157,22 @@ pub fn extract_records(spec: &OpenAPI) -> Result<BTreeMap<String, Record>> {
         .collect::<Result<_>>()?;
     Ok(result)
 }
+
+#[cfg(test)]
+mod tests {
+    use openapiv3::{OpenAPI, ReferenceOr, Schema, SchemaData, SchemaKind};
+    use crate::extractor::record::create_record_from_all_of;
+
+    #[test]
+    fn test_all_of_required_set_correctly() {
+        let mut additional_props: Schema = serde_yaml::from_str(include_str!("./pet_tag.yaml")).unwrap();
+        let SchemaKind::AllOf { all_of } = &additional_props.schema_kind else { panic!() };
+        let spec = OpenAPI::default();
+        let rec = create_record_from_all_of("PetTag", &all_of, &SchemaData::default(), &spec);
+        let mut fields = rec.fields();
+        let eye_color = fields.next().unwrap();
+        let weight = fields.next().unwrap();
+        assert_eq!(eye_color.optional, false);
+        assert_eq!(weight.optional, true);
+    }
+}
\ No newline at end of file
diff --git a/core/src/hir.rs b/core/src/hir.rs
index 99c322e..6ac2527 100644
--- a/core/src/hir.rs
+++ b/core/src/hir.rs
@@ -233,6 +233,7 @@ pub struct StrEnum {
     pub variants: Vec<String>,
 }
 
+// an object type in the HIR
 #[derive(Debug, Clone)]
 pub enum Record {
     Struct(Struct),
diff --git a/libninja/tests/all_of/main.rs b/libninja/tests/all_of/main.rs
index 6f31b1c..29a9678 100644
--- a/libninja/tests/all_of/main.rs
+++ b/libninja/tests/all_of/main.rs
@@ -35,6 +35,7 @@ fn test_transaction() {
 
     let record = record_for_schema("Transaction", TRANSACTION, &spec);
     let code = formatted_code(record);
+    println!("{}", code);
     assert_eq!(code, TRANSACTION_RS);
 }
 
diff --git a/libninja/tests/all_of/transaction.rs b/libninja/tests/all_of/transaction.rs
index 293c03f..24f35c1 100644
--- a/libninja/tests/all_of/transaction.rs
+++ b/libninja/tests/all_of/transaction.rs
@@ -6,12 +6,15 @@ pub struct Transaction {
     pub authorized_date: Option<chrono::NaiveDate>,
     #[serde(skip_serializing_if = "Option::is_none")]
     pub authorized_datetime: Option<chrono::DateTime<chrono::Utc>>,
-    pub counterparties: Vec<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub counterparties: Option<Vec<String>>,
     #[serde(skip_serializing_if = "Option::is_none")]
     pub datetime: Option<chrono::DateTime<chrono::Utc>>,
     pub payment_channel: String,
-    pub personal_finance_category: String,
-    pub personal_finance_category_icon_url: String,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub personal_finance_category: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub personal_finance_category_icon_url: Option<String>,
     pub transaction_code: String,
 }
 impl std::fmt::Display for Transaction {