diff --git a/xmlschemas.c b/xmlschemas.c
index b9c61b82..d276faf1 100644
--- a/xmlschemas.c
+++ b/xmlschemas.c
@@ -22744,7 +22744,7 @@ xmlSchemaXPathProcessHistory(xmlSchemaValidCtxtPtr vctxt,
 		} else if (pos >= matcher->sizeKeySeqs) {
 		    int i = matcher->sizeKeySeqs;
 
-		    matcher->sizeKeySeqs *= 2;
+		    matcher->sizeKeySeqs = pos * 2;
 		    matcher->keySeqs = (xmlSchemaPSVIIDCKeyPtr **)
 			xmlRealloc(matcher->keySeqs,
 			matcher->sizeKeySeqs *