diff --git a/infra/helper.py b/infra/helper.py
index 22c81984d..de1684a5b 100755
--- a/infra/helper.py
+++ b/infra/helper.py
@@ -751,12 +751,16 @@ def coverage(args):
   run_args.extend([
       '-v',
       '%s:/out' % _get_output_dir(args.project_name),
-      '-p',
-      '%s:%s' % (args.port, args.port),
       '-t',
       'gcr.io/oss-fuzz-base/base-runner',
   ])
 
+  if args.port:
+    run_args.extend([
+        '-p',
+        '%s:%s' % (args.port, args.port),
+    ])
+
   run_args.append('coverage')
   if args.fuzz_target:
     run_args.append(args.fuzz_target)