diff --git a/scripts/bundle_clusterfuzz.py b/scripts/bundle_clusterfuzz.py
index 941384cfc40..96940af3c47 100755
--- a/scripts/bundle_clusterfuzz.py
+++ b/scripts/bundle_clusterfuzz.py
@@ -115,7 +115,8 @@
     '--disable-relaxed-atomics',
 ]
 
-with tarfile.open(output_file, "w:gz") as tar:
+# Use fast compression (level 1) to speed up bundling with only a modest size increase.
+with tarfile.open(output_file, 'w:gz', compresslevel=1) as tar:
     # run.py
     run = os.path.join(shared.options.binaryen_root, 'scripts', 'clusterfuzz', 'run.py')
     print(f'  .. run:         {run}')