Index: library/nx/nx.tcl
===================================================================
diff -u -N -rcd7387dce218900697565aeabc0e58afb0294a6a -rc790d82b4b9e44e1d8e2a303e1d4931a91f049d8
--- library/nx/nx.tcl	(.../nx.tcl)	(revision cd7387dce218900697565aeabc0e58afb0294a6a)
+++ library/nx/nx.tcl	(.../nx.tcl)	(revision c790d82b4b9e44e1d8e2a303e1d4931a91f049d8)
@@ -1641,7 +1641,7 @@
   #
   # Define "superclass" as a ObjectParameterSlot defined as alias
   #
-  ::nx::ObjectParameterSlot create ::nx::Class::slot::superclass \
+  ::nx::ObjectParameterSlot create ::nx::Class::slot::superclasses \
       -methodname "::nsf::methods::class::superclass" \
       -elementtype class \
       -multiplicity 1..n \