diff --git a/mat64/qr_test.go b/mat64/qr_test.go
index cc7f219c..2447d2e0 100644
--- a/mat64/qr_test.go
+++ b/mat64/qr_test.go
@@ -63,6 +63,14 @@ func (s *S) TestQRD(c *check.C) {
 				{19.4, 5.2, -26.1},
 			},
 		},
+		{
+			name: "Fat",
+			a: [][]float64{
+				{1.3, 2.4, 8.9, 19.4},
+				{-2.6, 8.7, 9.1, 5.2},
+				{5.6, 5.8, 2.1, -26.1},
+			},
+		},
 	} {
 
 		a := NewDense(flatten(test.a))