diff --git a/library/x509_create.c b/library/x509_create.c
index 17fc8fb..09ac69d 100644
--- a/library/x509_create.c
+++ b/library/x509_create.c
@@ -14,6 +14,7 @@
 #include "mbedtls/oid.h"
 #include "x509_oid.h"
 
+#include <limits.h>
 #include <string.h>
 
 #include "mbedtls/platform.h"