diff --git a/packages/design/package.json b/packages/design/package.json
index 659c27557f..6018bafd83 100755
--- a/packages/design/package.json
+++ b/packages/design/package.json
@@ -11,5 +11,8 @@
     "dist/**/*",
     "types/**/*"
   ],
-  "types": "types/index.d.ts"
+  "types": "types/index.d.ts",
+  "dependencies": {
+    "@oasis-engine/math": "0.5.2"
+  }
 }
diff --git a/packages/math/package.json b/packages/math/package.json
index 647f70a8a2..c54b12d1d7 100755
--- a/packages/math/package.json
+++ b/packages/math/package.json
@@ -12,8 +12,5 @@
   "files": [
     "dist/**/*",
     "types/**/*"
-  ],
-  "devDependencies": {
-    "@oasis-engine/design": "0.5.2"
-  }
+  ]
 }
diff --git a/packages/math/src/BoundingBox.ts b/packages/math/src/BoundingBox.ts
index 538ef5bcec..d991cbb8bc 100644
--- a/packages/math/src/BoundingBox.ts
+++ b/packages/math/src/BoundingBox.ts
@@ -1,4 +1,4 @@
-import { IClone } from "@oasis-engine/design";
+import { IClone } from "./IClone";
 import { BoundingSphere } from "./BoundingSphere";
 import { Matrix } from "./Matrix";
 import { Vector3 } from "./Vector3";
diff --git a/packages/math/src/BoundingFrustum.ts b/packages/math/src/BoundingFrustum.ts
index 975e28ba6e..c1daa57c7b 100644
--- a/packages/math/src/BoundingFrustum.ts
+++ b/packages/math/src/BoundingFrustum.ts
@@ -1,4 +1,4 @@
-import { IClone } from "@oasis-engine/design";
+import { IClone } from "./IClone";
 import { BoundingBox } from "./BoundingBox";
 import { BoundingSphere } from "./BoundingSphere";
 import { CollisionUtil } from "./CollisionUtil";
diff --git a/packages/math/src/BoundingSphere.ts b/packages/math/src/BoundingSphere.ts
index 628b6531cd..0db173ff03 100644
--- a/packages/math/src/BoundingSphere.ts
+++ b/packages/math/src/BoundingSphere.ts
@@ -1,4 +1,4 @@
-import { IClone } from "@oasis-engine/design";
+import { IClone } from "./IClone";
 import { BoundingBox } from "./BoundingBox";
 import { Vector3 } from "./Vector3";
 
diff --git a/packages/math/src/Color.ts b/packages/math/src/Color.ts
index ff5198c88e..fe0e959326 100644
--- a/packages/math/src/Color.ts
+++ b/packages/math/src/Color.ts
@@ -1,4 +1,4 @@
-import { IClone } from "@oasis-engine/design";
+import { IClone } from "./IClone";
 import { MathUtil } from "./MathUtil";
 
 /**
diff --git a/packages/math/src/IClone.ts b/packages/math/src/IClone.ts
new file mode 100644
index 0000000000..88bf04a002
--- /dev/null
+++ b/packages/math/src/IClone.ts
@@ -0,0 +1,16 @@
+/**
+ * Clone interface.
+ */
+export interface IClone {
+  /**
+   * Clone and return object.
+   * @returns Clone object
+   */
+  clone(): Object;
+
+  /**
+   * Clone to the target object.
+   * @param target - Target object
+   */
+  cloneTo(target: Object): Object;
+}
diff --git a/packages/math/src/Matrix.ts b/packages/math/src/Matrix.ts
index d6a1924070..f4e9b88db7 100644
--- a/packages/math/src/Matrix.ts
+++ b/packages/math/src/Matrix.ts
@@ -1,4 +1,4 @@
-import { IClone } from "@oasis-engine/design";
+import { IClone } from "./IClone";
 import { MathUtil } from "./MathUtil";
 import { Matrix3x3 } from "./Matrix3x3";
 import { Quaternion } from "./Quaternion";
diff --git a/packages/math/src/Matrix3x3.ts b/packages/math/src/Matrix3x3.ts
index 304520d716..e5ee0e607c 100644
--- a/packages/math/src/Matrix3x3.ts
+++ b/packages/math/src/Matrix3x3.ts
@@ -1,4 +1,4 @@
-import { IClone } from "@oasis-engine/design";
+import { IClone } from "./IClone";
 import { MathUtil } from "./MathUtil";
 import { Matrix } from "./Matrix";
 import { Quaternion } from "./Quaternion";
diff --git a/packages/math/src/Plane.ts b/packages/math/src/Plane.ts
index 46d65db82b..eaff0163b3 100644
--- a/packages/math/src/Plane.ts
+++ b/packages/math/src/Plane.ts
@@ -1,4 +1,4 @@
-import { IClone } from "@oasis-engine/design";
+import { IClone } from "./IClone";
 import { Vector3 } from "./Vector3";
 
 /**
diff --git a/packages/math/src/Quaternion.ts b/packages/math/src/Quaternion.ts
index e83e355c0e..8c5b28fba4 100644
--- a/packages/math/src/Quaternion.ts
+++ b/packages/math/src/Quaternion.ts
@@ -1,4 +1,4 @@
-import { IClone } from "@oasis-engine/design";
+import { IClone } from "./IClone";
 import { MathUtil } from "./MathUtil";
 import { Matrix3x3 } from "./Matrix3x3";
 import { Vector3 } from "./Vector3";
diff --git a/packages/math/src/Rect.ts b/packages/math/src/Rect.ts
index 838bff501e..af371ebcf7 100644
--- a/packages/math/src/Rect.ts
+++ b/packages/math/src/Rect.ts
@@ -1,4 +1,4 @@
-import { IClone } from "@oasis-engine/design";
+import { IClone } from "./IClone";
 
 // A 2d rectangle defined by x and y position, width and height.
 export class Rect implements IClone {
diff --git a/packages/math/src/SphericalHarmonics3.ts b/packages/math/src/SphericalHarmonics3.ts
index c9fe995659..e60db6c0a9 100644
--- a/packages/math/src/SphericalHarmonics3.ts
+++ b/packages/math/src/SphericalHarmonics3.ts
@@ -1,4 +1,4 @@
-import { IClone } from "@oasis-engine/design";
+import { IClone } from "./IClone";
 import { Color } from "./Color";
 import { Vector3 } from "./Vector3";
 
@@ -203,7 +203,8 @@ export class SphericalHarmonics3 implements IClone {
    * @param out - The specified SphericalHarmonics3
    * @returns The specified SphericalHarmonics3
    */
-  cloneTo(out: SphericalHarmonics3): void {
+  cloneTo(out: SphericalHarmonics3): SphericalHarmonics3 {
     this.toArray(out.coefficients);
+    return out;
   }
 }
diff --git a/packages/math/src/Vector2.ts b/packages/math/src/Vector2.ts
index 12af206f42..a4ee1ec855 100644
--- a/packages/math/src/Vector2.ts
+++ b/packages/math/src/Vector2.ts
@@ -1,4 +1,4 @@
-import { IClone } from "@oasis-engine/design";
+import { IClone } from "./IClone";
 import { MathUtil } from "./MathUtil";
 
 /**
diff --git a/packages/math/src/Vector3.ts b/packages/math/src/Vector3.ts
index 381dd22a91..b238f9be8b 100644
--- a/packages/math/src/Vector3.ts
+++ b/packages/math/src/Vector3.ts
@@ -1,4 +1,4 @@
-import { IClone } from "@oasis-engine/design";
+import { IClone } from "./IClone";
 import { MathUtil } from "./MathUtil";
 import { Matrix } from "./Matrix";
 import { Quaternion } from "./Quaternion";
diff --git a/packages/math/src/Vector4.ts b/packages/math/src/Vector4.ts
index 60af696950..83f460daeb 100644
--- a/packages/math/src/Vector4.ts
+++ b/packages/math/src/Vector4.ts
@@ -1,4 +1,4 @@
-import { IClone } from "@oasis-engine/design";
+import { IClone } from "./IClone";
 import { MathUtil } from "./MathUtil";
 import { Matrix } from "./Matrix";
 import { Quaternion } from "./Quaternion";