diff --git a/library/x509.c b/library/x509.c
index 17c7a7d..13081e3 100644
--- a/library/x509.c
+++ b/library/x509.c
@@ -750,7 +750,7 @@
     unsigned char c;
     const x509_name *name;
     const char *short_name = NULL;
-    char s[128], *p;
+    char s[X509_MAX_DN_NAME_SIZE], *p;
 
     memset( s, 0, sizeof( s ) );