diff --git a/l3kernel/build.lua b/l3kernel/build.lua
index 4b4cb22490..5c9b6308fe 100644
--- a/l3kernel/build.lua
+++ b/l3kernel/build.lua
@@ -49,11 +49,11 @@ dofile(maindir .. "/build-config.lua")
 function update_tag(file,content,tagname,tagdate)
   local iso = "%d%d%d%d%-%d%d%-%d%d"
   local url = "https://github.com/latex3/latex3/compare/"
-  if string.match(content,"Copyright%s*%(C%)%s*[%d%-,]+") then
+  if string.match(content,"%(C%)%s*[%d%-,]+ The LaTeX3 Project") then
     local year = os.date("%Y")
     content = string.gsub(content,
-      "Copyright%s*%(C%)%s*([%d%-,]+)",
-      "Copyright (C) %1," .. year)
+      "%(C%)%s*([%d%-,]+)",
+      "(C) %1," .. year)
    content = string.gsub(content,year .. "," .. year,year)
    content = string.gsub(content,
      "%-" .. year - 1 .. "," .. year,