diff --git a/tests/test_cells.py b/tests/test_cells.py
index 7633944b..c332f2a5 100644
--- a/tests/test_cells.py
+++ b/tests/test_cells.py
@@ -2,6 +2,10 @@ from rich import cells
 
 
 def test_set_cell_size():
+    assert cells.set_cell_size("foo", 0) == ""
+    assert cells.set_cell_size("f", 0) == ""
+    assert cells.set_cell_size("", 0) == ""
+    assert cells.set_cell_size("😽😽", 0) == ""
     assert cells.set_cell_size("foo", 2) == "fo"
     assert cells.set_cell_size("foo", 3) == "foo"
     assert cells.set_cell_size("foo", 4) == "foo "