diff -r 75abdd7f2568 roundup/cgi/templating.py
--- a/roundup/cgi/templating.py	Thu Jul 30 17:16:32 2026 -0400
+++ b/roundup/cgi/templating.py	Mon Aug 03 00:21:26 2026 +0000
@@ -3753,6 +3753,22 @@
     def keywords_expressions(self, request):
         return render_keywords_expression_editor(request)
 
+    @staticmethod
+    def localReplace(message):
+        """Default no-op for localReplace.
+
+           Override with real definition in extensions.
+
+           This allows templates to ship with localReplace(....)
+           and have an:
+
+               instance.registerUtil('localReplace', local_replace)
+
+           define local_replace with the same call signature (i.e. no self)
+           in the extension definition.
+        """
+        return message
+
     def html_calendar(self, request):
         """Generate a HTML calendar.
 
diff -r 75abdd7f2568 roundup/instance.py
--- a/roundup/instance.py	Thu Jul 30 17:16:32 2026 -0400
+++ b/roundup/instance.py	Mon Aug 03 00:21:26 2026 +0000
@@ -262,7 +262,12 @@
            instead.
 
         """
-        self.templating_utils[name] = function
+        # allow templating util defined in extensions
+        # to replace the one defined in core.
+        if hasattr(self.TemplatingUtils, name):
+            setattr(self.TemplatingUtils, name, staticmethod(function))
+        else:
+            self.templating_utils[name] = function
 
     def registerUtilMethod(self, name, function):
         """Register a method that can be called using: