diff --git a/mlpp/lin_alg/mlpp_matrix.cpp b/mlpp/lin_alg/mlpp_matrix.cpp
index 8713d98..83504cf 100644
--- a/mlpp/lin_alg/mlpp_matrix.cpp
+++ b/mlpp/lin_alg/mlpp_matrix.cpp
@@ -665,28 +665,36 @@ void MLPPMatrix::subb(const Ref<MLPPMatrix> &A, const Ref<MLPPMatrix> &B) {
 }
 
 void MLPPMatrix::mult(const Ref<MLPPMatrix> &B) {
-	ERR_FAIL_MSG("TODO");
-
 	ERR_FAIL_COND(!B.is_valid());
 
 	Size2i b_size = B->size();
 
 	ERR_FAIL_COND(_size.x != b_size.y || _size.y != b_size.x);
 
-	//TODO need to make a copy of this, resize, and use that to get results into this
+	Ref<MLPPMatrix> A = duplicate();
+	Size2i a_size = A->size();
 
+	Size2i rs = Size2i(b_size.x, a_size.y);
+
+	if (_size != rs) {
+		resize(rs);
+	}
+
+	fill(0);
+
+	const real_t *a_ptr = A->ptr();
 	const real_t *b_ptr = B->ptr();
 	real_t *c_ptr = ptrw();
 
-	for (int ay = 0; ay < _size.y; ay++) {
+	for (int ay = 0; ay < a_size.y; ay++) {
 		for (int by = 0; by < b_size.y; by++) {
-			int ind_ay_by = calculate_index(ay, by);
+			int ind_ay_by = A->calculate_index(ay, by);
 
 			for (int bx = 0; bx < b_size.x; bx++) {
 				int ind_ay_bx = calculate_index(ay, bx);
 				int ind_by_bx = B->calculate_index(by, bx);
 
-				c_ptr[ind_ay_bx] += c_ptr[ind_ay_by] * b_ptr[ind_by_bx];
+				c_ptr[ind_ay_bx] += a_ptr[ind_ay_by] * b_ptr[ind_by_bx];
 			}
 		}
 	}
@@ -717,8 +725,6 @@ Ref<MLPPMatrix> MLPPMatrix::multn(const Ref<MLPPMatrix> &B) const {
 				int ind_k_j = B->calculate_index(k, j);
 
 				c_ptr[ind_i_j] += a_ptr[ind_i_k] * b_ptr[ind_k_j];
-
-				//C->set_element(i, j, C->get_element(i, j) + get_element(i, k) * B->get_element(k, j
 			}
 		}
 	}
@@ -752,8 +758,6 @@ void MLPPMatrix::multb(const Ref<MLPPMatrix> &A, const Ref<MLPPMatrix> &B) {
 				int ind_k_j = B->calculate_index(k, j);
 
 				c_ptr[ind_i_j] += a_ptr[ind_i_k] * b_ptr[ind_k_j];
-
-				//C->set_element(i, j, C->get_element(i, j) + A->get_element(i, k) * B->get_element(k, j
 			}
 		}
 	}
diff --git a/test/mlpp_tests.cpp b/test/mlpp_tests.cpp
index 60abbea..ac9174e 100644
--- a/test/mlpp_tests.cpp
+++ b/test/mlpp_tests.cpp
@@ -1353,6 +1353,50 @@ void MLPPTests::test_mlpp_matrix() {
 	is_approx_equals_mat(rmat, rmat2, "re-set_from_std_vectors test.");
 }
 
+void MLPPTests::test_mlpp_matrix_mul() {
+	std::vector<std::vector<real_t>> A = {
+		{ 1, 2 },
+		{ 3, 4 },
+		{ 5, 6 },
+		{ 7, 8 }
+	};
+
+	std::vector<std::vector<real_t>> B = {
+		{ 1, 2, 3, 4 },
+		{ 5, 6, 7, 8 }
+	};
+
+	std::vector<std::vector<real_t>> C = {
+		{ 11, 14, 17, 20 },
+		{ 23, 30, 37, 44 },
+		{ 35, 46, 57, 68 },
+		{ 47, 62, 77, 92 }
+	};
+
+	Ref<MLPPMatrix> rmata;
+	rmata.instance();
+	rmata->set_from_std_vectors(A);
+
+	Ref<MLPPMatrix> rmatb;
+	rmatb.instance();
+	rmatb->set_from_std_vectors(B);
+
+	Ref<MLPPMatrix> rmatc;
+	rmatc.instance();
+	rmatc->set_from_std_vectors(C);
+
+	Ref<MLPPMatrix> rmatr1 = rmata->multn(rmatb);
+	is_approx_equals_mat(rmatr1, rmatc, "Ref<MLPPMatrix> rmatr1 = rmata->multn(rmatb);");
+
+	Ref<MLPPMatrix> rmatr2;
+	rmatr2.instance();
+	rmatr2->multb(rmata, rmatb);
+	is_approx_equals_mat(rmatr2, rmatc, "rmatr2->multb(rmata, rmatb);");
+
+	rmata->mult(rmatb);
+	is_approx_equals_mat(rmata, rmatc, "rmata->mult(rmatb);");
+}
+
 void MLPPTests::is_approx_equalsd(real_t a, real_t b, const String &str) {
 	if (!Math::is_equal_approx(a, b)) {
 		ERR_PRINT("TEST FAILED: " + str + " Got: " + String::num(a) + " Should be: " + String::num(b));
@@ -1580,4 +1624,5 @@ void MLPPTests::_bind_methods() {
 
 	ClassDB::bind_method(D_METHOD("test_mlpp_vector"), &MLPPTests::test_mlpp_vector);
 	ClassDB::bind_method(D_METHOD("test_mlpp_matrix"), &MLPPTests::test_mlpp_matrix);
+	ClassDB::bind_method(D_METHOD("test_mlpp_matrix_mul"), &MLPPTests::test_mlpp_matrix_mul);
 }
diff --git a/test/mlpp_tests.h b/test/mlpp_tests.h
index a88d1b0..e993274 100644
--- a/test/mlpp_tests.h
+++ b/test/mlpp_tests.h
@@ -66,6 +66,7 @@ public:
 
 	void test_mlpp_vector();
 	void test_mlpp_matrix();
+	void test_mlpp_matrix_mul();
 
 	void is_approx_equalsd(real_t a, real_t b, const String &str);
 	void is_approx_equals_dvec(const Vector<real_t> &a, const Vector<real_t> &b, const String &str);