diff --git a/kevm-pyk/src/kevm_pyk/gst_to_kore.py b/kevm-pyk/src/kevm_pyk/gst_to_kore.py
index 01ee590267..5c63e1a28c 100644
--- a/kevm-pyk/src/kevm_pyk/gst_to_kore.py
+++ b/kevm-pyk/src/kevm_pyk/gst_to_kore.py
@@ -28,41 +28,64 @@
 SORT_MODE: Final = SortApp('SortMode')
 SORT_ETHEREUM_SIMULATION: Final = SortApp('SortEthereumSimulation')
 
-GST_DISCARD_KEYS: Final = [
-    '//',
-    '_info',
-    'callcreates',
-    'sealEngine',
-    'transactionSequence',
-    'chainname',
-    'expectException',
-    'lastblockhash',
-]
-GST_LOAD_KEYS: Final = ['env', 'pre', 'rlp', 'network', 'genesisRLP']
-GST_EXEC_KEYS: Final = ['exec', 'blocks']
-GST_POST_KEYS: Final = ['post', 'postState', 'postStateHash']
-GST_ALL_POST_KEYS: Final = GST_POST_KEYS + ['expect', 'export']
-GST_CHECK_KEYS: Final = GST_ALL_POST_KEYS + [
-    'logs',
-    'out',
-    'gas',
-    'blockHeader',
-    'transactions',
-    'uncleHeaders',
-    'genesisBlockHeader',
-    'withdrawals',
-    'blocknumber',
-]
+_GST_DISCARD_KEYS: Final = frozenset(
+    [
+        '//',
+        '_info',
+        'callcreates',
+        'sealEngine',
+        'transactionSequence',
+        'chainname',
+        'expectException',
+        'lastblockhash',
+    ]
+)
+_GST_LOAD_KEYS: Final = frozenset(
+    [
+        'env',
+        'pre',
+        'rlp',
+        'network',
+        'genesisRLP',
+    ]
+)
+_GST_EXEC_KEYS: Final = frozenset(
+    [
+        'exec',
+        'blocks',
+    ]
+)
+_GST_POST_KEYS: Final = frozenset(
+    [
+        'post',
+        'postState',
+        'postStateHash',
+    ]
+)
+_GST_ALL_POST_KEYS: Final = _GST_POST_KEYS.union(['expect', 'export'])
+_GST_CHECK_KEYS: Final = _GST_ALL_POST_KEYS.union(
+    [
+        'logs',
+        'out',
+        'gas',
+        'blockHeader',
+        'transactions',
+        'uncleHeaders',
+        'genesisBlockHeader',
+        'withdrawals',
+        'blocknumber',
+    ]
+)
 
 
 def filter_gst_keys(gst_data: dict) -> dict:
     """Filters the discarded keys out of a single GeneralStateTest.
 
     :param gst_data: A single test from a GST file structured as {"test_name": {test_fields}, ... }.
-    :returns: The gst_data object after filtering out GST_DISCARD_KEYS.
+    :returns: The gst_data object after filtering out _GST_DISCARD_KEYS.
     """
     return {
-        test_name: {k: v for k, v in test_data.items() if k not in GST_DISCARD_KEYS}
+        test_name: {k: v for k, v in test_data.items() if k not in _GST_DISCARD_KEYS}
         for test_name, test_data in gst_data.items()
     }