diff --git a/README.md b/README.md
index f9dc607..d683979 100644
--- a/README.md
+++ b/README.md
@@ -19,7 +19,7 @@
 </p>
 
 <p align="center">
-	<img alt="Version 3.2.1" src="https://img.shields.io/badge/version-3.2.1-blue" />
+	<img alt="Version 3.2.2" src="https://img.shields.io/badge/version-3.2.2-blue" />
 </p>
 
 ## Introduction
diff --git a/package.json b/package.json
index ba55fcf..23a9cdc 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
 	"name": "@sharkitek/core",
-	"version": "3.2.1",
+	"version": "3.2.2",
 	"description": "TypeScript library for well-designed model architectures.",
 	"keywords": [
 		"deserialization",
diff --git a/src/Model/Model.ts b/src/Model/Model.ts
index dc7d63c..36b4daa 100644
--- a/src/Model/Model.ts
+++ b/src/Model/Model.ts
@@ -243,7 +243,7 @@ export function model<ModelType extends Model<Shape, IdentifierType<Shape, Ident
 			{
 				this.forEachModelProperty((propertyName, propertyDefinition) => {
 					// For each property, set its original value to its current property value.
-					this._originalProperties[propertyName] = (this as PropertiesModel<Shape>)[propertyName];
+					this._originalProperties[propertyName] = structuredClone(this as PropertiesModel<Shape>)[propertyName];
 					propertyDefinition.type.resetDiff((this as PropertiesModel<Shape>)[propertyName]);
 				});
 			}
diff --git a/src/Model/Types/ArrayType.ts b/src/Model/Types/ArrayType.ts
index cd1d738..ee0bd71 100644
--- a/src/Model/Types/ArrayType.ts
+++ b/src/Model/Types/ArrayType.ts
@@ -54,6 +54,40 @@ export class ArrayType<SerializedValueType, SharkitekValueType> extends Type<Ser
 		// Reset diff of all elements.
 		value.forEach((value) => this.valueDefinition.type.resetDiff(value));
 	}
+
+	propertyHasChanged(originalValue: SharkitekValueType[]|null|undefined, currentValue: SharkitekValueType[]|null|undefined): boolean
+	{
+		// If any array length is different, arrays are different.
+		if (originalValue?.length != currentValue?.length) return true;
+		// If length is undefined, values are probably not arrays.
+		if (originalValue?.length == undefined) return false;
+
+		for (const key of originalValue.keys())
+		{ // Check for any change for each value in the array.
+			if (this.valueDefinition.type.propertyHasChanged(originalValue[key], currentValue[key]))
+				// The value has changed, the array is different.
+				return true;
+		}
+
+		return false; // No change detected.
+	}
+
+	serializedPropertyHasChanged(originalValue: SerializedValueType[] | null | undefined, currentValue: SerializedValueType[] | null | undefined): boolean
+	{
+		// If any array length is different, arrays are different.
+		if (originalValue?.length != currentValue?.length) return true;
+		// If length is undefined, values are probably not arrays.
+		if (originalValue?.length == undefined) return false;
+
+		for (const key of originalValue.keys())
+		{ // Check for any change for each value in the array.
+			if (this.valueDefinition.type.serializedPropertyHasChanged(originalValue[key], currentValue[key]))
+				// The value has changed, the array is different.
+				return true;
+		}
+
+		return false; // No change detected.
+	}
 }
 
 /**
diff --git a/src/Model/Types/ModelType.ts b/src/Model/Types/ModelType.ts
index b1641f6..9cfe1ba 100644
--- a/src/Model/Types/ModelType.ts
+++ b/src/Model/Types/ModelType.ts
@@ -48,6 +48,15 @@ export class ModelType<Shape extends ModelShape> extends Type<SerializedModel<Sh
 		// Reset diff of the given model.
 		value?.resetDiff();
 	}
+
+	propertyHasChanged(originalValue: Model<Shape>|null|undefined, currentValue: Model<Shape>|null|undefined): boolean
+	{
+		if (originalValue === undefined) return currentValue !== undefined;
+		if (originalValue === null) return currentValue !== null;
+
+		// If the current value is dirty, property has changed.
+		return currentValue.isDirty();
+	}
 }
 
 /**
diff --git a/src/Model/Types/ObjectType.ts b/src/Model/Types/ObjectType.ts
index b2af673..a036b17 100644
--- a/src/Model/Types/ObjectType.ts
+++ b/src/Model/Types/ObjectType.ts
@@ -66,6 +66,46 @@ export class ObjectType<Shape extends ModelShape> extends Type<SerializedModel<S
 			fieldDefinition.type.resetDiff(value?.[fieldName]);
 		});
 	}
+
+	propertyHasChanged(originalValue: PropertiesModel<Shape>|null|undefined, currentValue: PropertiesModel<Shape>|null|undefined): boolean
+	{
+		// Get keys arrays.
+		const originalKeys = Object.keys(originalValue) as (keyof Shape)[];
+		const currentKeys = Object.keys(currentValue) as (keyof Shape)[];
+
+		if (originalKeys.join(",") != currentKeys.join(","))
+			// Keys have changed, objects are different.
+			return true;
+
+		for (const key of originalKeys)
+		{ // Check for any change for each value in the object.
+			if (this.shape[key].type.propertyHasChanged(originalValue[key], currentValue[key]))
+				// The value has changed, the object is different.
+				return true;
+		}
+
+		return false; // No change detected.
+	}
+
+	serializedPropertyHasChanged(originalValue: SerializedModel<Shape>|null|undefined, currentValue: SerializedModel<Shape>|null|undefined): boolean
+	{
+		// Get keys arrays.
+		const originalKeys = Object.keys(originalValue) as (keyof Shape)[];
+		const currentKeys = Object.keys(currentValue) as (keyof Shape)[];
+
+		if (originalKeys.join(",") != currentKeys.join(","))
+			// Keys have changed, objects are different.
+			return true;
+
+		for (const key of originalKeys)
+		{ // Check for any change for each value in the object.
+			if (this.shape[key].type.serializedPropertyHasChanged(originalValue[key], currentValue[key]))
+				// The value has changed, the object is different.
+				return true;
+		}
+
+		return false; // No change detected.
+	}
 }
 
 /**
diff --git a/tests/Model.test.ts b/tests/Model.test.ts
index 36aa9b9..03ecc63 100644
--- a/tests/Model.test.ts
+++ b/tests/Model.test.ts
@@ -142,23 +142,21 @@ it("save with modified submodels", () => {
 		title: "this is a test",
 		authors: [
 			{ name: "DOE", firstName: "John", email: "test@test.test", createdAt: (new Date()).toISOString(), active: true, },
-			{ name: "TEST", firstName: "Another", email: "another@test.test", createdAt: (new Date()).toISOString(), active: false, },
+			{ name: "TEST", firstName: "Another", email: "another@test.test", createdAt: (new Date("1997-09-09")).toISOString(), active: false, },
 		],
 		text: "this is a long test.",
 		evaluation: "25.23",
 		tags: [ {name: "test"}, {name: "foo"} ],
 	});
 
-	article.authors = article.authors.map((author) => {
-		author.name = "TEST";
-		return author;
-	});
+	article.authors[0].name = "TEST";
+	article.authors[1].createdAt.setMonth(9);
 
 	expect(article.save()).toStrictEqual({
 		id: 1,
 		authors: [
-			{ name: "TEST", },
-			{}, //{ name: "TEST", firstName: "Another", email: "another@test.test" },
+			{ name: "TEST" },
+			{ createdAt: (new Date("1997-10-09")).toISOString() }, //{ name: "TEST", firstName: "Another", email: "another@test.test" },
 		],
 	});
 });