diff --git a/src/nifreeze/utils/iterators.py b/src/nifreeze/utils/iterators.py
index e3fdb696..5429324a 100644
--- a/src/nifreeze/utils/iterators.py
+++ b/src/nifreeze/utils/iterators.py
@@ -193,10 +193,10 @@ def bvalue_iterator(*_, **kwargs) -> Iterator[int]:
     [0, 1, 8, 4, 5, 2, 3, 6, 7]
 
     """
-    bvals = kwargs.get(BVALS_KWARG, None)
+    bvals = kwargs.pop(BVALS_KWARG, None)
     if bvals is None:
         raise TypeError(KWARG_ERROR_MSG.format(kwarg=BVALS_KWARG))
-    return _value_iterator(bvals, round_decimals=2, ascending=True)
+    return _value_iterator(bvals, ascending=True, **kwargs)
 
 
 def uptake_iterator(*_, **kwargs) -> Iterator[int]:
@@ -225,10 +225,10 @@ def uptake_iterator(*_, **kwargs) -> Iterator[int]:
     [3, 7, 1, 8, 2, 5, 6, 0, 4]
 
     """
-    uptake = kwargs.get(UPTAKE_KWARG, None)
+    uptake = kwargs.pop(UPTAKE_KWARG, None)
     if uptake is None:
         raise TypeError(KWARG_ERROR_MSG.format(kwarg=UPTAKE_KWARG))
-    return _value_iterator(uptake, round_decimals=2, ascending=False)
+    return _value_iterator(uptake, ascending=False, **kwargs)
 
 
 def centralsym_iterator(size: int | None = None, **kwargs) -> Iterator[int]:
diff --git a/test/test_iterators.py b/test/test_iterators.py
index b774c17b..be2b63a3 100644
--- a/test/test_iterators.py
+++ b/test/test_iterators.py
@@ -38,35 +38,49 @@
 
 
 @pytest.mark.parametrize(
-    "values, ascending, expected",
+    "values, ascending, round_decimals, expected",
     [
         # Simple integers
-        ([1, 2, 3], True, [0, 1, 2]),
-        ([1, 2, 3], False, [2, 1, 0]),
+        ([1, 2, 3], True, 2, [0, 1, 2]),
+        ([1, 2, 3], False, 2, [2, 1, 0]),
         # Repeated values
-        ([2, 1, 2, 1], True, [1, 3, 0, 2]),
-        ([2, 1, 2, 1], False, [2, 0, 3, 1]),  # Ties are reversed due to reverse=True
+        ([2, 1, 2, 1], True, 2, [1, 3, 0, 2]),
+        ([2, 1, 2, 1], False, 2, [2, 0, 3, 1]),  # Ties are reversed due to reverse=True
         # Floats
-        ([1.01, 1.02, 0.99], True, [2, 0, 1]),
-        ([1.01, 1.02, 0.99], False, [1, 0, 2]),
+        ([1.01, 1.02, 0.99], True, 2, [2, 0, 1]),
+        ([1.01, 1.02, 0.99], False, 2, [1, 0, 2]),
         # Floats with rounding
         (
             [1.001, 1.002, 0.999],
             True,
+            2,
             [0, 1, 2],
         ),  # All round to 1.00 (round_decimals=2), so original order
+        (
+            [1.001, 1.002, 0.999],
+            True,
+            4,
+            [2, 0, 1],
+        ),
         (
             [1.001, 1.002, 0.999],
             False,
+            2,
             [2, 1, 0],
         ),  # All round to 1.00 (round_decimals=2), ties are reversed due to reverse=True
+        (
+            [1.001, 1.002, 0.999],
+            False,
+            4,
+            [1, 0, 2],
+        ),
         # Negative and positive
-        ([-1.2, 0.0, 3.4, -1.2], True, [0, 3, 1, 2]),
-        ([-1.2, 0.0, 3.4, -1.2], False, [2, 1, 3, 0]),  # Ties are reversed due to reverse=True
+        ([-1.2, 0.0, 3.4, -1.2], True, 2, [0, 3, 1, 2]),
+        ([-1.2, 0.0, 3.4, -1.2], False, 2, [2, 1, 3, 0]),  # Ties are reversed due to reverse=True
     ],
 )
-def test_value_iterator(values, ascending, expected):
-    result = list(_value_iterator(values, ascending=ascending))
+def test_value_iterator(values, ascending, round_decimals, expected):
+    result = list(_value_iterator(values, ascending=ascending, round_decimals=round_decimals))
     assert result == expected