diff --git a/quic/test_tools/failing_proof_source.cc b/quic/test_tools/failing_proof_source.cc
index 645bef9..1f17c8a 100644
--- a/quic/test_tools/failing_proof_source.cc
+++ b/quic/test_tools/failing_proof_source.cc
@@ -23,7 +23,8 @@
 FailingProofSource::GetCertChain(const QuicSocketAddress& /*server_address*/,
                                  const QuicSocketAddress& /*client_address*/,
                                  const std::string& /*hostname*/,
-                                 bool* /*cert_matched_sni*/) {
+                                 bool* cert_matched_sni) {
+  *cert_matched_sni = false;
   return QuicReferenceCountedPointer<Chain>();
 }