diff --git a/tests/test_selection.py b/tests/test_selection.py
index 021af9d22..99d87f584 100644
--- a/tests/test_selection.py
+++ b/tests/test_selection.py
@@ -21,3 +21,9 @@ def test_selection(server, s22):
 
     vis.selection = [0, 7, 6, 5, 4]
     assert vis.selection == [0, 7, 6, 5, 4]
+
+    with pytest.raises(ValueError):
+        vis.selection = [0, 0, 2]
+
+    with pytest.raises(ValueError):
+        vis.selection = "Hello"
diff --git a/zndraw/zndraw.py b/zndraw/zndraw.py
index 0b026b96e..98c670570 100644
--- a/zndraw/zndraw.py
+++ b/zndraw/zndraw.py
@@ -252,8 +252,12 @@ def selection(self) -> list[int]:
 
     @selection.setter
     def selection(self, value: list[int]):
+        if not isinstance(value, list):
+            raise ValueError("Selection must be a list")
         if not all(isinstance(x, int) for x in value):
             raise ValueError("Selection must be a list of integers")
+        if len(value) != len(set(value)):
+            raise ValueError("Selection must not contain duplicates")
 
         max_index = len(self.atoms)
         if any(x >= max_index for x in value):