diff --git a/packages/testing/src/execution_testing/specs/blockchain.py b/packages/testing/src/execution_testing/specs/blockchain.py
index a7ab9a9ecd..acb24f1def 100644
--- a/packages/testing/src/execution_testing/specs/blockchain.py
+++ b/packages/testing/src/execution_testing/specs/blockchain.py
@@ -848,7 +848,7 @@ def generate_block_data(
             ]
         txs = [tx.with_signature_and_sender() for tx in txs]
 
-        if failing_tx_count := len([tx for tx in txs if tx.error]) > 0:
+        if (failing_tx_count := len([tx for tx in txs if tx.error])) > 0:
             if failing_tx_count > 1:
                 raise Exception(
                     "test correctness: only one transaction can produce "