diff --git a/test/core/tsi/crl_ssl_transport_security_test.cc b/test/core/tsi/crl_ssl_transport_security_test.cc
index bb7e4e938aa..b13f6a0f1a7 100644
--- a/test/core/tsi/crl_ssl_transport_security_test.cc
+++ b/test/core/tsi/crl_ssl_transport_security_test.cc
@@ -19,6 +19,8 @@
 #include <gmock/gmock.h>
 #include <gtest/gtest.h>
 
+#include "absl/strings/str_cat.h"
+
 #include <grpc/grpc.h>
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>