diff --git a/infra/gcb/build_and_run_coverage.py b/infra/gcb/build_and_run_coverage.py
index 0017d7fb4..fc943e28f 100644
--- a/infra/gcb/build_and_run_coverage.py
+++ b/infra/gcb/build_and_run_coverage.py
@@ -121,6 +121,7 @@ def get_build_steps(project_dir):
 
   # Split fuzz targets into batches of CORPUS_DOWNLOAD_BATCH_SIZE.
   for i in xrange(0,  len(fuzz_targets), CORPUS_DOWNLOAD_BATCH_SIZE):
+    download_corpus_args = []
     for binary_name in fuzz_targets[i : i+CORPUS_DOWNLOAD_BATCH_SIZE]:
       qualified_name = binary_name
       qualified_name_prefix = '%s_' % project_name