diff --git a/tests/conftest.py b/tests/conftest.py
index f454c2b9..67fa3b95 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -19,10 +19,21 @@
 
 
 @pytest.fixture(autouse=True)
-def fast_mode():
-    boa.env.enable_fast_mode()
+def boa_setup():
+    import tracemalloc
+
+    tracemalloc.start()
+    snapshot = tracemalloc.take_snapshot()
+    # boa.env.enable_fast_mode()
     yield
+    boa.env._contracts.clear()
+    boa.env._code_registry.clear()
     boa.reset_env()
+    snapshot2 = tracemalloc.take_snapshot()
+    top_stats = snapshot2.compare_to(snapshot, "lineno")
+    print("[ Top 10 differences ]")
+    for stat in top_stats[:10]:
+        print(stat)
 
 
 def pytest_generate_tests(metafunc):