diff --git a/src/math/Matrices/Matrix.js b/src/math/Matrices/Matrix.js
index 91d3ecc263..e7d9748904 100644
--- a/src/math/Matrices/Matrix.js
+++ b/src/math/Matrices/Matrix.js
@@ -1856,9 +1856,12 @@ export class Matrix extends MatrixInterface {
    * @chainable
    */
   #transpose3x3(mat3) {
-    if (mat3 === undefined) {
+    if (mat3 instanceof Matrix) {
+      mat3 = mat3.mat3;
+    } else if (mat3 === undefined) {
       mat3 = this.mat3;
     }
+
     const a01 = mat3[1];
     const a02 = mat3[2];
     const a12 = mat3[5];
diff --git a/test/unit/math/p5.Matrix.js b/test/unit/math/p5.Matrix.js
index 762d7f3779..7e0f03ca67 100644
--- a/test/unit/math/p5.Matrix.js
+++ b/test/unit/math/p5.Matrix.js
@@ -406,20 +406,18 @@ suite('p5.Matrix', function () {
       ]);
     });
 
-    // TODO: matrix transpose This needs to be added to the legacy tests
-    it.skip('should transpose a 3x3 matrix correctly', () => {
+    it('should transpose a 3x3 matrix correctly', () => {
       const mat = new p5.Matrix([1, 2, 3, 4, 5, 6, 7, 8, 9]);
       mat.transpose(mat);
-      expect(mat.mat3).toEqual([1, 4, 7, 2, 5, 8, 3, 6, 9]);
+      expect(toArray(mat.mat3)).toEqual([1, 4, 7, 2, 5, 8, 3, 6, 9]);
     });
 
-    // TODO: matrix transpose This needs to be added to the legacy tests
-    it.skip('should transpose a 3x3 matrix from an array correctly', () => {
+    it('should transpose a 3x3 matrix from an array correctly', () => {
       const mat = new p5.Matrix([1, 2, 3, 4, 5, 6, 7, 8, 9]);
 
       mat.transpose([1, 2, 3, 4, 5, 6, 7, 8, 9]);
 
-      expect(mat.mat3).toEqual([1, 4, 7, 2, 5, 8, 3, 6, 9]);
+      expect(toArray(mat.mat3)).toEqual([1, 4, 7, 2, 5, 8, 3, 6, 9]);
     });
   });
   describe.skip('Determinant', () => {