diff --git a/test/functional/feature_init.py b/test/functional/feature_init.py
index 16815c1afc..4b56b0c26b 100755
--- a/test/functional/feature_init.py
+++ b/test/functional/feature_init.py
@@ -93,7 +93,7 @@ class InitStressTest(BitcoinTestFramework):
             additional_lines = random.randint(1, num_total_logs)
             self.log.debug(f"Starting node and will exit after {additional_lines} lines")
             node.start(extra_args=['-txindex=1'])
-            logfile = open(node.debug_log_path, 'r', encoding='utf8')
+            logfile = open(node.debug_log_path, 'rb')
 
             MAX_SECS_TO_WAIT = 10
             start = time.time()