diff --git a/src/daemon/https/minitasn1/coding.c b/src/daemon/https/minitasn1/coding.c
index 385577a0..af28be4c 100644
--- a/src/daemon/https/minitasn1/coding.c
+++ b/src/daemon/https/minitasn1/coding.c
@@ -626,8 +626,9 @@ _asn1_ordering_set (unsigned char *der, int der_len, node_asn * node)
     return;
 
   p = node->down;
-  while ((type_field (p->type) == TYPE_TAG)
-         || (type_field (p->type) == TYPE_SIZE))
+  while ( (p != NULL) &&
+	  ((type_field (p->type) == TYPE_TAG)
+	   || (type_field (p->type) == TYPE_SIZE)) )
     p = p->right;
 
   if ((p == NULL) || (p->right == NULL))