diff --git a/python/binaryview.py b/python/binaryview.py
index 54898478d..cdc5b1a2d 100644
--- a/python/binaryview.py
+++ b/python/binaryview.py
@@ -2466,10 +2466,8 @@ def __getitem__(self, i: Union[int, slice]) -> Union['_function.Function', List[
 			return _function.Function(self._view, core.BNNewFunctionReference(self._funcs[i]))
 		elif isinstance(i, slice):
 			result = []
-			if i.start < 0 or i.start >= len(self) or i.stop < 0 or i.stop >= len(self):
-				raise IndexError(f"Slice {i} out of bounds for FunctionList of size {len(self)}")
-
-			for j in range(i.start, i.stop, i.step if i.step is not None else 1):
+			start, stop, step = i.indices(len(self))
+			for j in range(start, stop, step):
 				result.append(_function.Function(self._view, core.BNNewFunctionReference(self._funcs[j])))
 			return result
 		raise ValueError("FunctionList.__getitem__ supports argument of type integer or slice")
diff --git a/python/function.py b/python/function.py
index a592efba5..86c5b33b6 100644
--- a/python/function.py
+++ b/python/function.py
@@ -279,10 +279,8 @@ def __getitem__(self, i: Union[int, slice]) -> Union['basicblock.BasicBlock', Li
 			return self._function._instantiate_block(block)
 		elif isinstance(i, slice):
 			result = []
-			if i.start < 0 or i.start >= len(self) or i.stop < 0 or i.stop >= len(self):
-				raise IndexError(f"Slice {i} out of bounds for BasicBlockList of size {len(self)}")
-
-			for j in range(i.start, i.stop, i.step if i.step is not None else 1):
+			start, stop, step = i.indices(len(self))
+			for j in range(start, stop, step):
 				block = core.BNNewBasicBlockReference(self._blocks[j])
 				assert block is not None, "core.BNNewBasicBlockReference returned None"
 				result.append(self._function._instantiate_block(block))
@@ -400,10 +398,8 @@ def __getitem__(
 			return arch, self._tags[i].addr, binaryview.Tag(core_tag)
 		elif isinstance(i, slice):
 			result = []
-			if i.start < 0 or i.start >= len(self) or i.stop < 0 or i.stop >= len(self):
-				raise IndexError(f"Slice {i} out of bounds for TagList of size {len(self)}")
-
-			for j in range(i.start, i.stop, i.step if i.step is not None else 1):
+			start, stop, step = i.indices(len(self))
+			for j in range(start, stop, step):
 				core_tag = core.BNNewTagReference(self._tags[j].tag)
 				assert core_tag is not None, "core.BNNewTagReference returned None"
 				arch = architecture.CoreArchitecture._from_cache(self._tags[j].arch)