diff --git a/sed/calibrator/energy.py b/sed/calibrator/energy.py
index ec19f72e..d09d5923 100644
--- a/sed/calibrator/energy.py
+++ b/sed/calibrator/energy.py
@@ -1732,10 +1732,8 @@ def peakdetect1d(
     if lookahead < 1:
         raise ValueError("Lookahead must be '1' or above in value")
 
-    if not (np.isscalar(delta) and cast(int, delta) >= 0):
+    if not (np.ndim(delta) == 0 and delta >= 0):
         raise ValueError("delta must be a positive number")
-    # Hack because TypeGuard with numpy 1.22.4 seems broken
-    delta = cast(int, delta)
 
     # maxima and minima candidates are temporarily stored in
     # mx and mn respectively
diff --git a/tests/test_binning.py b/tests/test_binning.py
index fceceb78..74062cb5 100644
--- a/tests/test_binning.py
+++ b/tests/test_binning.py
@@ -1,7 +1,6 @@
 """This file contains code that performs several tests for the sed.binning module
 """
 from typing import Any
-from typing import cast
 from typing import List
 from typing import Sequence
 from typing import Tuple
@@ -394,9 +393,8 @@ def test_simplify_binning_arguments(
         ranges_,
     )
 
-    for i, bin_ in enumerate(bins__):
-        # TODO: Why does typing fail?
-        np.testing.assert_array_equal(cast(np.ndarray, bin_), bins_expected[i])
+    for i, _ in enumerate(bins__):
+        np.testing.assert_array_equal(bins__[i], bins_expected[i])
         np.testing.assert_array_equal(axes__[i], axes_expected[i])
         if ranges__ is not None:
             np.testing.assert_array_equal(ranges__[i], ranges_expected[i])