diff --git a/relaxng.c b/relaxng.c
index 57ae972..8d88e95 100644
--- a/relaxng.c
+++ b/relaxng.c
@@ -6652,12 +6652,17 @@
     ctxt->define = NULL;
     if (IS_RELAXNG(node, "grammar")) {
         schema->topgrammar = xmlRelaxNGParseGrammar(ctxt, node->children);
+        if (schema->topgrammar == NULL) {
+            xmlRelaxNGFree(schema);
+            return (NULL);
+        }
     } else {
         xmlRelaxNGGrammarPtr tmp, ret;
 
         schema->topgrammar = ret = xmlRelaxNGNewGrammar(ctxt);
         if (schema->topgrammar == NULL) {
-            return (schema);
+            xmlRelaxNGFree(schema);
+            return (NULL);
         }
         /*
          * Link the new grammar in the tree
diff --git a/tree.c b/tree.c
index 7853e35..7d41481 100644
--- a/tree.c
+++ b/tree.c
@@ -4514,6 +4514,10 @@
 #ifdef LIBXML_TREE_ENABLED
     if (doc->intSubset != NULL) {
         ret->intSubset = xmlCopyDtd(doc->intSubset);
+	if (ret->intSubset == NULL) {
+	    xmlFreeDoc(ret);
+	    return(NULL);
+	}
 	xmlSetTreeDoc((xmlNodePtr)ret->intSubset, ret);
 	ret->intSubset->parent = ret;
     }