diff --git a/test/fuzz/test_runner.py b/test/fuzz/test_runner.py
--- a/test/fuzz/test_runner.py
+++ b/test/fuzz/test_runner.py
@@ -130,6 +130,7 @@
             build_dir=config["environment"]["BUILDDIR"],
             merge_dir=args.m_dir,
         )
+        return
 
     run_once(
         corpus=args.seed_dir,