diff --git a/py21cmnet/tests/test_utils.py b/py21cmnet/tests/test_utils.py
index 5f3095b..6954d13 100644
--- a/py21cmnet/tests/test_utils.py
+++ b/py21cmnet/tests/test_utils.py
@@ -77,14 +77,14 @@ def test_parse_activation():
     
 
 def test_load_21cmfast():
-    a = np.random.randn(1000).astype(np.float).reshape(10, 10, 10)
+    a = np.random.randn(1000).astype(np.float64).reshape(10, 10, 10)
     fname = os.path.join(DATA_PATH, "_xyz_testfile")
     a.tofile(fname)
 
-    box = utils.load_21cmfast(fname, dtype=np.float, N=10)
+    box = utils.load_21cmfast(fname, dtype=np.float64, N=10)
     assert np.isclose(a, box).all()
 
-    box = utils.load_21cmfast([fname, fname], dtype=np.float, N=10)
+    box = utils.load_21cmfast([fname, fname], dtype=np.float64, N=10)
     assert np.isclose(a, np.array([box, box])).all()
 
     os.remove(fname)