diff --git a/valid.c b/valid.c
index 120627cc..4352a08b 100644
--- a/valid.c
+++ b/valid.c
@@ -879,6 +879,8 @@ xmlValidCtxtPtr xmlNewValidCtxt(void) {
  */
 void
 xmlFreeValidCtxt(xmlValidCtxtPtr cur) {
+    if (cur == NULL)
+        return;
     if (cur->vstateTab != NULL)
         xmlFree(cur->vstateTab);
     if (cur->nodeTab != NULL)