diff --git a/webif/lib/xml.class b/webif/lib/xml.class
index 7cde513..8c3025e 100644
--- a/webif/lib/xml.class
+++ b/webif/lib/xml.class
@@ -2,7 +2,7 @@
 # From https://wiki.tcl-lang.org/page/Parsing+XML
 # Keith Vetter 2004-03-01
 
-if {![exists -proc class]} { package require oo }
+if {![exists -command class]} { package require oo }
 
 class xml {
 	xml	""