diff --git a/eth/precompiles/modexp.py b/eth/precompiles/modexp.py
index f971bd4b93..e477ce6013 100644
--- a/eth/precompiles/modexp.py
+++ b/eth/precompiles/modexp.py
@@ -35,7 +35,7 @@ def _compute_complexity(length):
             length ** 2 // 4 + 96 * length - 3072
         )
     else:
-        return 2 ** 2 // 16 + 480 * length - 199680
+        return length ** 2 // 16 + 480 * length - 199680
 
 
 def _extract_lengths(data):
diff --git a/tests/json-fixtures/test_state.py b/tests/json-fixtures/test_state.py
index 9e42524b5b..71d0ee0159 100644
--- a/tests/json-fixtures/test_state.py
+++ b/tests/json-fixtures/test_state.py
@@ -138,11 +138,6 @@ def expand_fixtures_forks(all_fixtures):
 # Ideally, this list should be empty.
 # WHEN ADDING ENTRIES, ALWAYS PROVIDE AN EXPLANATION!
 INCORRECT_UPSTREAM_TESTS = {
-    # Upstream seems to specify that the precompile call fails, but `py-evm`
-    # handles it just fine.
-    # * https://github.com/ethereum/py-evm/pull/1224#issuecomment-417351843
-    # * https://github.com/ethereum/tests/pull/405#issuecomment-417855812
-    ('stReturnDataTest/modexp_modsize0_returndatasize.json', 'modexp_modsize0_returndatasize', 'Byzantium', 4),  # noqa: E501
 }