diff --git a/src/powerbox/tools.py b/src/powerbox/tools.py
index cbc7b80..d03d500 100644
--- a/src/powerbox/tools.py
+++ b/src/powerbox/tools.py
@@ -1120,7 +1120,9 @@ def get_power(
         dim = len(deltax.shape)
 
         if not np.iterable(boxlength):
-            boxlength = [boxlength] * dim
+            boxlength = [float(boxlength)] * dim
+        else:
+            boxlength = [float(val) for val in boxlength]
 
         if deltax2 is not None and deltax.shape != deltax2.shape:
             raise ValueError("deltax and deltax2 must have the same shape!")
diff --git a/tests/test_tools.py b/tests/test_tools.py
index 4041def..47c5ee8 100644
--- a/tests/test_tools.py
+++ b/tests/test_tools.py
@@ -459,6 +459,9 @@ def test_cross_power_identity():
     p, k = get_power(dx, pb.boxlength, b=1)
     p_cross, k = get_power(dx, pb.boxlength, b=1, deltax2=dx)
     assert np.all(np.isclose(p, p_cross))
+    p, k = get_power(dx, [1, 1], b=1)
+    p_cross, k = get_power(dx, [1, 1], b=1, deltax2=dx)
+    assert np.all(np.isclose(p, p_cross))
 
 
 @pytest.mark.skip()