diff --git a/tests/micropython/extreme_exc.py b/tests/micropython/extreme_exc.py
index 9d2f24745..ad819e408 100644
--- a/tests/micropython/extreme_exc.py
+++ b/tests/micropython/extreme_exc.py
@@ -126,8 +126,8 @@ def main():
         )
     except Exception as er:
         e = er
-    lst[0][0] = None
-    lst = None
+    while lst:
+        lst[0], lst = None, lst[0]  # unlink lists to free up heap
     print(repr(e)[:10])
 
     # raise a deep exception with the heap locked