diff --git a/light/test_light.cc b/light/test_light.cc
index 2dcc2ae9..897b01de 100644
--- a/light/test_light.cc
+++ b/light/test_light.cc
@@ -867,3 +867,47 @@ TEST(mathlib, octree_basic) {
         EXPECT_EQ(objsTouchingObj_i, objsTouchingObj_i_octree);
     }
 }
+
+TEST(qvec, matrix2x2inv) {
+    std::mt19937 engine(0);
+    std::uniform_real_distribution<float> dis(-4096, 4096);
+    
+    qmat2x2f randMat;
+    for (int i=0; i<2; i++)
+        for (int j=0; j<2; j++)
+            randMat[i][j] = dis(engine);
+    
+    bool ok;
+    qmat2x2f randInv = qv::invert(randMat, &ok);
+    ASSERT_TRUE(ok);
+    
+    qmat2x2f prod = randMat * randInv;
+    for (int i=0; i<2; i++) {
+        for (int j=0; j<2; j++) {
+            float exp = (i == j) ? 1.0f : 0.0f;
+            ASSERT_TRUE(fabs(exp - prod[i][j]) < 0.001);
+        }
+    }
+}
+
+TEST(qvec, matrix4x4inv) {
+    std::mt19937 engine(0);
+    std::uniform_real_distribution<float> dis(-4096, 4096);
+    
+    qmat4x4f randMat;
+    for (int i=0; i<4; i++)
+        for (int j=0; j<4; j++)
+            randMat[i][j] = dis(engine);
+    
+    bool ok;
+    qmat4x4f randInv = qv::invert(randMat, &ok);
+    ASSERT_TRUE(ok);
+    
+    qmat4x4f prod = randMat * randInv;
+    for (int i=0; i<4; i++) {
+        for (int j=0; j<4; j++) {
+            float exp = (i == j) ? 1.0f : 0.0f;
+            ASSERT_TRUE(fabs(exp - prod[i][j]) < 0.001);
+        }
+    }
+}