diff --git a/test/test_net_speed.py b/test/test_net_speed.py
index 754150a4a7..8093246032 100644
--- a/test/test_net_speed.py
+++ b/test/test_net_speed.py
@@ -77,7 +77,7 @@ class TestConvSpeed(unittest.TestCase):
       x = Tensor.randn(128, 1, 28, 28)
       x = x.conv2d(c1).relu().avg_pool2d()
       x = x.conv2d(c2).relu().max_pool2d()
-      x = x.reshape(Tensor(np.array((x.shape[0], -1))))
+      x = x.reshape(shape=(x.shape[0], -1))
       out = x.dot(l1).logsoftmax()
       out = out.mean()
       et1 = time.time()
diff --git a/tinygrad/tensor.py b/tinygrad/tensor.py
index a45eecfd71..cca9369466 100644
--- a/tinygrad/tensor.py
+++ b/tinygrad/tensor.py
@@ -13,9 +13,11 @@ class Tensor:
     elif type(data) != np.ndarray:
       print("error constructing tensor with %r" % data)
       assert(False)
+    if data.dtype != np.float32:
+      # warning? float64 is actually needed for numerical jacobian
+      pass
 
-    # only float32
-    self.data = data.astype(np.float32)
+    self.data = data
     self.grad = None
 
     # internal variables used for autograd graph construction