diff --git a/curriculum/challenges/english/07-scientific-computing-with-python/learn-classes-and-objects-by-building-a-sudoku-solver/660ac35d55a15d81afdedd76.md b/curriculum/challenges/english/07-scientific-computing-with-python/learn-classes-and-objects-by-building-a-sudoku-solver/660ac35d55a15d81afdedd76.md
index 1c7a3e36ed7..3e9be29342e 100644
--- a/curriculum/challenges/english/07-scientific-computing-with-python/learn-classes-and-objects-by-building-a-sudoku-solver/660ac35d55a15d81afdedd76.md
+++ b/curriculum/challenges/english/07-scientific-computing-with-python/learn-classes-and-objects-by-building-a-sudoku-solver/660ac35d55a15d81afdedd76.md
@@ -20,7 +20,12 @@ You should declare a variable `row_str`.
 You should assign a list comprehension that iterates over `row` to the `row_str` variable.
 
 ```js
-({ test: () => assert(runPython(`_Node(_code).find_class("Board").find_function("__str__").find_for_loops()[0].find_bodies()[0].find_variable("row_str").find_comp_iters()[0].is_equivalent("row")`)) })
+({ test: () => (runPython(`
+import ast
+var = _Node(_code).find_class("Board").find_function("__str__").find_for_loops()[0].find_bodies()[0].find_variable("row_str")
+assert var.find_comp_iters()[0].is_equivalent("row"), "You should iterate over row"
+assert isinstance(var.tree.value, ast.ListComp), "It's not a list comprehension"
+`)) })
 ```
 
 The list comprehension assigned to the `row_str` variable should use `i` as iteration variable.