Index: openacs-4/packages/acs-tcl/tcl/defs-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-tcl/tcl/defs-procs.tcl,v
diff -u -r1.81.2.1 -r1.81.2.2
--- openacs-4/packages/acs-tcl/tcl/defs-procs.tcl	31 Mar 2019 11:17:59 -0000	1.81.2.1
+++ openacs-4/packages/acs-tcl/tcl/defs-procs.tcl	30 Sep 2019 14:58:02 -0000	1.81.2.2
@@ -459,10 +459,13 @@
     @return The cached value.
 
 } {
-    if {$delete_p} {
+    set flush_p [expr {$delete_p || [info exists set]}]
+    if {$flush_p} {
         if {[nsv_exists ad_param_$key $parameter_name]} {
             nsv_unset ad_param_$key $parameter_name
         }
+    }
+    if {$delete_p} {
         return
     }
     if {[info exists set]} {