diff --git a/pw_presubmit/py/pw_presubmit/pigweed_presubmit.py b/pw_presubmit/py/pw_presubmit/pigweed_presubmit.py
index e8b70ab6bf..79f66f6357 100755
--- a/pw_presubmit/py/pw_presubmit/pigweed_presubmit.py
+++ b/pw_presubmit/py/pw_presubmit/pigweed_presubmit.py
@@ -218,7 +218,7 @@ def _gn_combined_build_check_targets() -> Sequence[str]:
         project='codesearch',
         trace_type='LLVM',
         trim_prefix='/b/s/w/ir/x/w/co',
-        ref='main',
+        ref='refs/heads/main',
         source='infra:main',
         owner='pigweed-infra@google.com',
         bug_component='503634',