Index: openacs-4/packages/acs-tcl/tcl/memoize-procs-naviserver.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-tcl/tcl/memoize-procs-naviserver.tcl,v
diff -u -N -r1.8 -r1.9
--- openacs-4/packages/acs-tcl/tcl/memoize-procs-naviserver.tcl	5 Aug 2018 21:08:42 -0000	1.8
+++ openacs-4/packages/acs-tcl/tcl/memoize-procs-naviserver.tcl	11 Feb 2019 10:11:45 -0000	1.9
@@ -53,10 +53,19 @@
 
     @return The possibly-cached value returned by <i>script</i>.
 } {
-    if {$max_age ne ""} {
-        set max_age "-expires $max_age"
+    #
+    # The ::util_memoize_flush proc is defined in the *-init script,
+    # after the util_memoize cache was created. Therefore is save to
+    # use the util_memoize when this proc is available.
+    #
+    if {[info commands ::util_memoize_flush] ne ""} {
+        if {$max_age ne ""} {
+            set max_age "-expires $max_age"
+        }
+        ns_cache_eval {*}$max_age -- util_memoize $script {*}$script
+    } else {
+        uplevel $script
     }
-    ns_cache_eval {*}$max_age -- util_memoize $script {*}$script
 }
 
 # In case, the definition of the function has cached something,