diff --git a/lib/SimpleSAML/Metadata/SAMLBuilder.php b/lib/SimpleSAML/Metadata/SAMLBuilder.php
index ca7a419e1054c17bafb3c135b433759d1f697626..66afa93458876269efb0cdd835536ae79f5f2e75 100644
--- a/lib/SimpleSAML/Metadata/SAMLBuilder.php
+++ b/lib/SimpleSAML/Metadata/SAMLBuilder.php
@@ -630,7 +630,7 @@ class SAMLBuilder
 
         $e = new \SAML2\XML\md\IDPSSODescriptor();
         $e->setProtocolSupportEnumeration(
-            array_merge($e->getProtocolSupportEnumeration, [
+            array_merge($e->getProtocolSupportEnumeration(), [
                 'urn:oasis:names:tc:SAML:1.1:protocol',
                 'urn:mace:shibboleth:1.0'
             ])