diff --git a/c/tls.c b/c/tls.c
index 2264d2da2..377b68cc0 100644
--- a/c/tls.c
+++ b/c/tls.c
@@ -8,6 +8,7 @@
   Copyright Contributors to the Zowe Project.
 */
 #include <stdlib.h>
+#include <string.h>
 #include <sys/socket.h>
 #include <errno.h>
 #include "alloc.h"