diff --git a/spec/section/source-vocabulary.md b/spec/section/source-vocabulary.md
index e2c562c..207a21b 100644
--- a/spec/section/source-vocabulary.md
+++ b/spec/section/source-vocabulary.md
@@ -282,7 +282,7 @@ to iterate over.
         sd:endpoint  <http://example.com/sparql>;
         sd:supportedLanguage sd:SPARQL11Query;
     ];
-    rml:iterator "CONSTRUCT WHERE { ?s ?p ?o. } LIMIT 100";
+    rml:iterator "SELECT { s? ?p ?o } WHERE { ?s ?p ?o. } LIMIT 100";
     rml:referenceFormulation formats:SPARQL_Results_CSV;
 .
 </pre>