diff --git a/lib/std/math/math_matrix.c3 b/lib/std/math/math_matrix.c3
index 8129fd4d0..11a9978c1 100644
--- a/lib/std/math/math_matrix.c3
+++ b/lib/std/math/math_matrix.c3
@@ -197,7 +197,7 @@ fn Real Matrix4x4.determinant(&self)
 
 fn Matrix2x2 Matrix2x2.adjoint(&self)
 {
-	return { self.m00, -self.m01, -self.m10, self.m11 };
+	return { self.m11, -self.m01, -self.m10, self.m00 };
 }
 
 fn Matrix3x3 Matrix3x3.adjoint(&self)
diff --git a/test/unit/stdlib/math/matrix.c3 b/test/unit/stdlib/math/matrix.c3
index 97bb966d3..7eae62d0f 100644
--- a/test/unit/stdlib/math/matrix.c3
+++ b/test/unit/stdlib/math/matrix.c3
@@ -106,8 +106,17 @@ fn void test_mat2()
 		assert(calc.m == value.m);
 }
 
+fn void! test_mat2_inverse()
+{
+		Matrix2 a = { 3, 5, 6, 2 };
+		Matrix2 a_inv = a.inverse()!;
+		double sum = ((double[<4>])a_inv.mul(a).m).sum();
+		assert(math::abs(sum - 2.0) < math::FLOAT_EPSILON,
+			"wrong inverse: sum of all elements should be 2, but got: %g", sum);
+}
+
 fn void test_vec3()
 {
 	Vec3 cross = Vec3{2,3,4}.cross(Vec3{5,6,7});
 	assert(cross == Vec3{-3,6,-3});
-}
\ No newline at end of file
+}