diff --git a/src/test/util/setup_common.cpp b/src/test/util/setup_common.cpp
index bcf637784d7..8c832976722 100644
--- a/src/test/util/setup_common.cpp
+++ b/src/test/util/setup_common.cpp
@@ -307,8 +307,10 @@ ChainTestingSetup::ChainTestingSetup(const ChainType chainType, TestOpts opts)
             .check_block_index = 1,
             .notifications = *m_node.notifications,
             .signals = m_node.validation_signals.get(),
-            // Use no worker threads while fuzzing to avoid non-determinism
+            // Use no worker threads while fuzzing to avoid racy non-determinism
+            // and dangling thread handles if AFL forks after initialization.
             .worker_threads_num = EnableFuzzDeterminism() ? 0 : 2,
+            .prevoutfetch_threads_num = EnableFuzzDeterminism() ? 0 : 2,
         };
         if (opts.min_validation_cache) {
             chainman_opts.script_execution_cache_bytes = 0;