diff --git a/library/oid.c b/library/oid.c
index 7d7f1bf..2868ef9 100644
--- a/library/oid.c
+++ b/library/oid.c
@@ -15,6 +15,7 @@
 #include "mbedtls/rsa.h"
 #include "mbedtls/error.h"
 
+#include <limits.h>
 #include <stdio.h>
 #include <string.h>