diff --git a/src/xrt/auxiliary/util/u_json.c b/src/xrt/auxiliary/util/u_json.c
index 91c5f0eaf..3ff2fd6ca 100644
--- a/src/xrt/auxiliary/util/u_json.c
+++ b/src/xrt/auxiliary/util/u_json.c
@@ -15,6 +15,9 @@
 #include <stdio.h>
 
 #ifndef XRT_HAVE_SYSTEM_CJSON
+#if defined(_MSC_VER) && !defined(_CRT_SECURE_NO_WARNINGS)
+#define _CRT_SECURE_NO_WARNINGS
+#endif
 // This includes the c file completely.
 #include "cjson/cJSON.c"
 #endif