diff --git a/crypto/x509v3/v3_purp.c b/crypto/x509v3/v3_purp.c
index 13c512050..b03c323df 100644
--- a/crypto/x509v3/v3_purp.c
+++ b/crypto/x509v3/v3_purp.c
@@ -59,6 +59,7 @@
 
 #include <stdio.h>
 #include "internal/cryptlib.h"
+#include "internal/numbers.h"
 #include <openssl/x509v3.h>
 #include <openssl/x509_vfy.h>