diff --git a/jsonschema/json.go b/jsonschema/json.go
index c02d250aa..e4eef98e7 100644
--- a/jsonschema/json.go
+++ b/jsonschema/json.go
@@ -4,6 +4,8 @@
 // and/or pass in the schema in []byte format.
 package jsonschema
 
+import "encoding/json"
+
 type DataType string
 
 const (
@@ -17,7 +19,7 @@ const (
 )
 
 // Definition is a struct for describing a JSON Schema.
-// It is fairly limited and you may have better luck using a third-party library.
+// It is fairly limited, and you may have better luck using a third-party library.
 type Definition struct {
 	// Type specifies the data type of the schema.
 	Type DataType `json:"type,omitempty"`
@@ -33,3 +35,24 @@ type Definition struct {
 	// Items specifies which data type an array contains, if the schema type is Array.
 	Items *Definition `json:"items,omitempty"`
 }
+
+func (d *Definition) MarshalJSON() ([]byte, error) {
+	d.initializeProperties()
+	return json.Marshal(*d)
+}
+
+func (d *Definition) initializeProperties() {
+	if d.Properties == nil {
+		d.Properties = make(map[string]Definition)
+		return
+	}
+
+	for k, v := range d.Properties {
+		if v.Properties == nil {
+			v.Properties = make(map[string]Definition)
+		} else {
+			v.initializeProperties()
+		}
+		d.Properties[k] = v
+	}
+}
diff --git a/jsonschema/json_test.go b/jsonschema/json_test.go
new file mode 100644
index 000000000..0dc31a58a
--- /dev/null
+++ b/jsonschema/json_test.go
@@ -0,0 +1,201 @@
+package jsonschema_test
+
+import (
+	"encoding/json"
+	"reflect"
+	"testing"
+
+	. "github.com/sashabaranov/go-openai/jsonschema"
+)
+
+func TestDefinition_MarshalJSON(t *testing.T) {
+	tests := []struct {
+		name string
+		def  Definition
+		want string
+	}{
+		{
+			name: "Test with empty Definition",
+			def:  Definition{},
+			want: `{"properties":{}}`,
+		},
+		{
+			name: "Test with Definition properties set",
+			def: Definition{
+				Type:        String,
+				Description: "A string type",
+				Properties: map[string]Definition{
+					"name": {
+						Type: String,
+					},
+				},
+			},
+			want: `{
+   "type":"string",
+   "description":"A string type",
+   "properties":{
+      "name":{
+         "type":"string",
+         "properties":{}
+      }
+   }
+}`,
+		},
+		{
+			name: "Test with nested Definition properties",
+			def: Definition{
+				Type: Object,
+				Properties: map[string]Definition{
+					"user": {
+						Type: Object,
+						Properties: map[string]Definition{
+							"name": {
+								Type: String,
+							},
+							"age": {
+								Type: Integer,
+							},
+						},
+					},
+				},
+			},
+			want: `{
+   "type":"object",
+   "properties":{
+      "user":{
+         "type":"object",
+         "properties":{
+            "name":{
+               "type":"string",
+               "properties":{}
+            },
+            "age":{
+               "type":"integer",
+               "properties":{}
+            }
+         }
+      }
+   }
+}`,
+		},
+		{
+			name: "Test with complex nested Definition",
+			def: Definition{
+				Type: Object,
+				Properties: map[string]Definition{
+					"user": {
+						Type: Object,
+						Properties: map[string]Definition{
+							"name": {
+								Type: String,
+							},
+							"age": {
+								Type: Integer,
+							},
+							"address": {
+								Type: Object,
+								Properties: map[string]Definition{
+									"city": {
+										Type: String,
+									},
+									"country": {
+										Type: String,
+									},
+								},
+							},
+						},
+					},
+				},
+			},
+			want: `{
+   "type":"object",
+   "properties":{
+      "user":{
+         "type":"object",
+         "properties":{
+            "name":{
+               "type":"string",
+               "properties":{}
+            },
+            "age":{
+               "type":"integer",
+               "properties":{}
+            },
+            "address":{
+               "type":"object",
+               "properties":{
+                  "city":{
+                     "type":"string",
+                     "properties":{}
+                  },
+                  "country":{
+                     "type":"string",
+                     "properties":{}
+                  }
+               }
+            }
+         }
+      }
+   }
+}`,
+		},
+		{
+			name: "Test with Array type Definition",
+			def: Definition{
+				Type: Array,
+				Items: &Definition{
+					Type: String,
+				},
+				Properties: map[string]Definition{
+					"name": {
+						Type: String,
+					},
+				},
+			},
+			want: `{
+   "type":"array",
+   "items":{
+      "type":"string",
+      "properties":{
+         
+      }
+   },
+   "properties":{
+      "name":{
+         "type":"string",
+         "properties":{}
+      }
+   }
+}`,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			gotBytes, err := json.Marshal(&tt.def)
+			if err != nil {
+				t.Errorf("Failed to Marshal JSON: error = %v", err)
+				return
+			}
+
+			var got map[string]interface{}
+			err = json.Unmarshal(gotBytes, &got)
+			if err != nil {
+				t.Errorf("Failed to Unmarshal JSON: error =  %v", err)
+				return
+			}
+
+			wantBytes := []byte(tt.want)
+			var want map[string]interface{}
+			err = json.Unmarshal(wantBytes, &want)
+			if err != nil {
+				t.Errorf("Failed to Unmarshal JSON: error = %v", err)
+				return
+			}
+
+			if !reflect.DeepEqual(got, want) {
+				t.Errorf("MarshalJSON() got = %v, want %v", got, want)
+			}
+		})
+	}
+}