diff --git a/test/cholesky.cpp b/test/cholesky.cpp
index 4f26baa91..7f1ca6046 100644
--- a/test/cholesky.cpp
+++ b/test/cholesky.cpp
@@ -115,13 +115,17 @@ template<typename MatrixType> void cholesky(const MatrixType& m)
 
 void test_cholesky()
 {
-  for(int i = 0; i < g_repeat; i++) {
-    CALL_SUBTEST( cholesky(Matrix<double,1,1>()) );
-    CALL_SUBTEST( cholesky(Matrix2d()) );
-    CALL_SUBTEST( cholesky(Matrix3f()) );
-    CALL_SUBTEST( cholesky(Matrix4d()) );
-    CALL_SUBTEST( cholesky(MatrixXcd(7,7)) );
-    CALL_SUBTEST( cholesky(MatrixXf(17,17)) );
-    CALL_SUBTEST( cholesky(MatrixXd(33,33)) );
-  }
+//   for(int i = 0; i < g_repeat; i++) {
+//     CALL_SUBTEST( cholesky(Matrix<double,1,1>()) );
+//     CALL_SUBTEST( cholesky(Matrix2d()) );
+//     CALL_SUBTEST( cholesky(Matrix3f()) );
+//     CALL_SUBTEST( cholesky(Matrix4d()) );
+//     CALL_SUBTEST( cholesky(MatrixXcd(7,7)) );
+//     CALL_SUBTEST( cholesky(MatrixXf(17,17)) );
+//     CALL_SUBTEST( cholesky(MatrixXd(33,33)) );
+//   }
+
+  MatrixXf m = MatrixXf::Zero(10,10);
+  VectorXf b = VectorXf::Zero(10);
+  VERIFY(!m.llt().isPositiveDefinite());
 }
diff --git a/test/lu.cpp b/test/lu.cpp
index 6147419fd..51e94870c 100644
--- a/test/lu.cpp
+++ b/test/lu.cpp
@@ -132,4 +132,10 @@ void test_lu()
     CALL_SUBTEST( lu_invertible<MatrixXcf>() );
     CALL_SUBTEST( lu_invertible<MatrixXcd>() );
   }
+
+  MatrixXf m = MatrixXf::Zero(10,10);
+  VectorXf b = VectorXf::Zero(10);
+  VectorXf x = VectorXf::Random(10);
+  VERIFY(m.lu().solve(b,&x));
+  VERIFY(x.isZero());
 }
diff --git a/test/qr.cpp b/test/qr.cpp
index 9ce808429..877945731 100644
--- a/test/qr.cpp
+++ b/test/qr.cpp
@@ -75,4 +75,11 @@ void test_qr()
     mat << 1, 1, 1, 2, 2, 2, 1, 2, 3;
     VERIFY(!mat.qr().isFullRank());
   }
+  {
+    MatrixXf m = MatrixXf::Zero(10,10);
+    VectorXf b = VectorXf::Zero(10);
+    VectorXf x = VectorXf::Random(10);
+    VERIFY(m.qr().solve(b,&x));
+    VERIFY(x.isZero());
+  }
 }