diff --git a/src/core/tsi/ssl_transport_security.c b/src/core/tsi/ssl_transport_security.c
index 018ddc4456399fc79bf502ae9621bfffa733051b..b7c2859a1c9f09140f1ae31a85fc0099837943a3 100644
--- a/src/core/tsi/ssl_transport_security.c
+++ b/src/core/tsi/ssl_transport_security.c
@@ -34,6 +34,7 @@
 #include "src/core/tsi/ssl_transport_security.h"
 
 #include <limits.h>
+#include <string.h>
 
 #include <grpc/support/log.h>
 #include <grpc/support/sync.h>