Index: openacs-4/packages/acs-tcl/tcl/apm-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-tcl/tcl/apm-procs.tcl,v
diff -u -N -r1.95.2.8 -r1.95.2.9
--- openacs-4/packages/acs-tcl/tcl/apm-procs.tcl	16 Nov 2016 19:10:10 -0000	1.95.2.8
+++ openacs-4/packages/acs-tcl/tcl/apm-procs.tcl	28 Mar 2017 07:17:55 -0000	1.95.2.9
@@ -1699,15 +1699,25 @@
     }
 
     set test_arg_list ""
+    set test_arg_list_spec ""
     foreach arg_name [apm_arg_names_for_callback_type -type $type] {
         lappend test_arg_list -$arg_name value
+        lappend test_arg_list_spec -${arg_name}:required        
     }
 
     if { $test_arg_list eq "" } {
         # The callback proc should take no args
         return [expr {[info args ::$proc_name] eq ""}]
     }
+    
+    if {[info commands ::nsf::cmd::info] ne ""} {
+        #
+        # We can compare the signature of via nsf procs
+        #
+        return [expr {[::nsf::cmd::info parameter ::$proc_name] eq $test_arg_list_spec}]
 
+    }
+
     # The callback proc should have required arg switches. Check
     # that the ad_proc arg parser doesn't throw an error with
     # test arg list