diff --git a/.github/scripts/build_packages.py b/.github/scripts/build_packages.py
index e8c2ccfb..3a78a28a 100644
--- a/.github/scripts/build_packages.py
+++ b/.github/scripts/build_packages.py
@@ -9,8 +9,9 @@
 The templates in packaging/ hold the shape. This fills them from the one place
 each value lives: the version from the tag, the checksums from the release's
 own checksum file, the addresses from go.mod and web/public/CNAME, the date
-from CHANGELOG.md. Nothing is typed twice, and the two values that are - the
-product's name and its licence - are held to their Go originals by a guard.
+from CHANGELOG.md. Nothing is typed twice, and the three values that are - the
+product's name, its licence and its copyright line - are held to their Go
+originals by a guard.
 
 Usage:
     python .github/scripts/build_packages.py --tag v0.4.0 \\
@@ -50,6 +51,11 @@
 APP_NAME = "Testing Files Generator"
 LICENCE = "GPL-3.0-only"
 
+# The line tfg license prints, held by a guard to internal/version/version.go.
+# Chocolatey's moderation asked for it in the nuspec after 0.4.0, and it
+# refuses one shorter than four characters (rule CPMR0001).
+COPYRIGHT = "Copyright (C) 2026 DonislawDev"
+
 # The name both feeds show as the author, and the first part of the WinGet
 # identifiers - the same publisher folder the sibling project already has in
 # winget-pkgs.
@@ -258,6 +264,7 @@ def values(package, version, tag, sums):
         "EXE": package.program + ".exe",
         "MONIKER": package.moniker,
         "LICENSE": LICENCE,
+        "COPYRIGHT": COPYRIGHT,
         "REPO_URL": repo_url,
         "PROJECT_URL": site(),
         "DOCS_URL": site() + "docs/",
diff --git a/internal/guard/packaging_test.go b/internal/guard/packaging_test.go
index b4bdb086..f3dc6267 100644
--- a/internal/guard/packaging_test.go
+++ b/internal/guard/packaging_test.go
@@ -457,6 +457,38 @@ func TestThePackagesNameTheProductAndLicenceTheProgramDoes(t *testing.T) {
 	}
 }
 
+// Every package carries, once, the copyright line tfg license prints.
+// Chocolatey's moderation asked for it after 0.4.0 and refuses one shorter than
+// four characters (rule CPMR0001), and winget show prints it. Read from what
+// the renderer wrote rather than from its copy, so a template that loses the
+// element fails here as surely as a copy that drifts from the program.
+func TestEveryPackageCarriesTheCopyrightTheProgramPrints(t *testing.T) {
+	lines := regexp.MustCompile(`(?m)^Copyright \(C\) .+$`).FindAllString(
+		readRepoFile(t, "internal/version/version.go"), -1)
+	if len(lines) != 1 {
+		t.Fatalf("internal/version/version.go holds %d copyright lines, not one - "+
+			"there is no single line to hold the packages to", len(lines))
+	}
+	nuspec := `<copyright>([^<]*)</copyright>`
+	locale := `(?m)^Copyright: (.*)$`
+	files := renderedPackages(t)
+	for _, pkg := range []struct{ file, pattern string }{
+		{windowChoco + "testing-files-generator.nuspec", nuspec},
+		{cliChoco + "testing-files-generator-cli.nuspec", nuspec},
+		{windowWinget + ".locale.en-US.yaml", locale},
+		{cliWinget + ".locale.en-US.yaml", locale},
+	} {
+		found := regexp.MustCompile(pkg.pattern).FindAllStringSubmatch(files[pkg.file], -1)
+		if len(found) != 1 {
+			t.Errorf("%s carries %d copyright lines, not one", pkg.file, len(found))
+			continue
+		}
+		if found[0][1] != lines[0] {
+			t.Errorf("%s gives the copyright as %q and tfg license as %q", pkg.file, found[0][1], lines[0])
+		}
+	}
+}
+
 // The package sources are in git. Chocolatey's moderation asks packageSourceUrl
 // to point at them, the job in ci.yml renders them on a fresh clone, and the
 // point of a package source is that somebody else can see what the package
diff --git a/packaging/README.md b/packaging/README.md
index 7989efe5..24d94bf4 100644
--- a/packaging/README.md
+++ b/packaging/README.md
@@ -4,8 +4,9 @@ These are **templates**, not packages. Every `{{PLACEHOLDER}}` is filled by
 `.github/scripts/build_packages.py` from the one place that owns the value: the
 version from the release tag, the checksums from that release's
 `verify-SHA256SUMS.txt`, the addresses from `go.mod` and `web/public/CNAME`, the
-release date from `CHANGELOG.md`. The two values the renderer keeps a copy of,
-the product name and the licence, are held to their Go originals by a guard.
+release date from `CHANGELOG.md`. The three values the renderer keeps a copy
+of, the product name, the licence and the copyright line, are held to their Go
+originals by a guard.
 
     python .github/scripts/build_packages.py --tag v0.4.0 \
         --sums verify-SHA256SUMS.txt --out <a directory outside the repository>
diff --git a/packaging/chocolatey/package.nuspec.in b/packaging/chocolatey/package.nuspec.in
index 7a9febb4..75e31f03 100644
--- a/packaging/chocolatey/package.nuspec.in
+++ b/packaging/chocolatey/package.nuspec.in
@@ -11,6 +11,7 @@
     <projectUrl>{{PROJECT_URL}}</projectUrl>
     <iconUrl>{{ICON_URL}}</iconUrl>
     <licenseUrl>{{LICENSE_URL}}</licenseUrl>
+    <copyright>{{COPYRIGHT}}</copyright>
     <requireLicenseAcceptance>false</requireLicenseAcceptance>
     <projectSourceUrl>{{REPO_URL}}</projectSourceUrl>
     <docsUrl>{{DOCS_URL}}</docsUrl>
diff --git a/packaging/winget/locale.en-US.yaml.in b/packaging/winget/locale.en-US.yaml.in
index eee61d6f..48736689 100644
--- a/packaging/winget/locale.en-US.yaml.in
+++ b/packaging/winget/locale.en-US.yaml.in
@@ -11,6 +11,7 @@ PackageName: {{TITLE}}
 PackageUrl: {{PROJECT_URL}}
 License: {{LICENSE}}
 LicenseUrl: {{LICENSE_URL}}
+Copyright: {{COPYRIGHT}}
 ShortDescription: {{SHORT_DESCRIPTION}}
 Description: |-
   {{DESCRIPTION}}