diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 92b1e06..c15cc51 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -55,71 +55,81 @@ jobs:
           NEW: ${{ inputs.version }}
         run: |
           python - <<'PY'
-          import os, re
+          import os, re, sys
           from pathlib import Path
 
           old = os.environ["OLD"]
           new = os.environ["NEW"]
           old_re = re.escape(old)
+          # Generic semver pattern. Used for packaging files where the
+          # version string may have drifted out of sync with app/constants.py
+          # (root cause of the v1.13.9 Snap Store freeze: snapcraft.yaml stayed
+          # at 1.13.9 from v1.13.10 onward because OLD no longer matched).
+          ANY = r"\d+\.\d+\.\d+"
 
-          # (path, list of (regex, replacement)) pairs.
-          # Each replacement uses {new} as the new version.
+          # (path, list of (regex, replacement), bool: required) tuples.
+          # required=True targets fail the job if no substitution happens.
           targets = [
               ("app/constants.py", [
                   (rf'APP_VERSION\s*=\s*"{old_re}"', f'APP_VERSION = "{new}"'),
-              ]),
+              ], True),
               ("installer.py", [
-                  (rf'APP_VERSION\s*=\s*"{old_re}"', f'APP_VERSION = "{new}"'),
-              ]),
+                  (rf'APP_VERSION\s*=\s*"{ANY}"', f'APP_VERSION = "{new}"'),
+              ], True),
               ("docs/index.html", [
-                  (rf'"softwareVersion":\s*"{old_re}"', f'"softwareVersion": "{new}"'),
+                  (rf'"softwareVersion":\s*"{ANY}"', f'"softwareVersion": "{new}"'),
                   (rf'v{old_re}', f'v{new}'),
-              ]),
+              ], True),
               ("docs/changelog.html", [
                   (rf'v{old_re}', f'v{new}'),
-              ]),
+              ], False),
               ("snap/snapcraft.yaml", [
-                  (rf"version:\s*'{old_re}'", f"version: '{new}'"),
-              ]),
+                  (rf"version:\s*'{ANY}'", f"version: '{new}'"),
+              ], True),
               ("rpm/pdfapps.spec", [
-                  (rf'^Version:\s+{old_re}', f'Version:        {new}'),
-              ]),
+                  (rf'^Version:\s+{ANY}', f'Version:        {new}'),
+              ], True),
               ("aur/pdfapps/PKGBUILD", [
-                  (rf'pkgver={old_re}', f'pkgver={new}'),
-              ]),
+                  (rf'pkgver={ANY}', f'pkgver={new}'),
+              ], True),
               ("aur/pdfapps/.SRCINFO", [
-                  (rf'pkgver = {old_re}', f'pkgver = {new}'),
-                  (rf'{old_re}', new),
-              ]),
+                  (rf'pkgver = {ANY}', f'pkgver = {new}'),
+                  (rf'pdfapps-{ANY}', f'pdfapps-{new}'),
+                  (rf'v{ANY}', f'v{new}'),
+              ], True),
               ("aur/pdfapps-bin/PKGBUILD", [
-                  (rf'pkgver={old_re}', f'pkgver={new}'),
-              ]),
+                  (rf'pkgver={ANY}', f'pkgver={new}'),
+              ], True),
               ("aur/pdfapps-bin/.SRCINFO", [
-                  (rf'pkgver = {old_re}', f'pkgver = {new}'),
-                  (rf'provides = pdfapps={old_re}', f'provides = pdfapps={new}'),
-                  (rf'v{old_re}', f'v{new}'),
-                  (rf'pdfapps-{old_re}', f'pdfapps-{new}'),
-              ]),
+                  (rf'pkgver = {ANY}', f'pkgver = {new}'),
+                  (rf'provides = pdfapps={ANY}', f'provides = pdfapps={new}'),
+                  (rf'v{ANY}', f'v{new}'),
+                  (rf'pdfapps-{ANY}', f'pdfapps-{new}'),
+              ], True),
               ("winget/nelsonduarte.PDFApps.installer.yaml", [
-                  (rf'PackageVersion:\s*{old_re}', f'PackageVersion: {new}'),
-                  (rf'v{old_re}', f'v{new}'),
-              ]),
+                  (rf'PackageVersion:\s*{ANY}', f'PackageVersion: {new}'),
+                  (rf'v{ANY}', f'v{new}'),
+              ], True),
               ("winget/nelsonduarte.PDFApps.locale.en-US.yaml", [
-                  (rf'PackageVersion:\s*{old_re}', f'PackageVersion: {new}'),
-                  (rf'v{old_re}', f'v{new}'),
-              ]),
+                  (rf'PackageVersion:\s*{ANY}', f'PackageVersion: {new}'),
+                  (rf'v{ANY}', f'v{new}'),
+              ], True),
               ("winget/nelsonduarte.PDFApps.yaml", [
-                  (rf'PackageVersion:\s*{old_re}', f'PackageVersion: {new}'),
-              ]),
+                  (rf'PackageVersion:\s*{ANY}', f'PackageVersion: {new}'),
+              ], True),
               ("flatpak/io.github.nelsonduarte.PDFApps.yml", [
-                  (rf'tag:\s*v{old_re}', f'tag: v{new}'),
-              ]),
+                  (rf'tag:\s*v{ANY}', f'tag: v{new}'),
+              ], True),
           ]
 
-          for path_str, subs in targets:
+          missing_required = []
+          stale_required = []
+          for path_str, subs, required in targets:
               p = Path(path_str)
               if not p.exists():
                   print(f"skip (missing): {path_str}")
+                  if required:
+                      missing_required.append(path_str)
                   continue
               text = p.read_text(encoding="utf-8")
               original = text
@@ -129,7 +139,20 @@ jobs:
                   p.write_text(text, encoding="utf-8")
                   print(f"updated: {path_str}")
               else:
-                  print(f"unchanged: {path_str}")
+                  # Already at the new version? Then unchanged is fine.
+                  if new in original:
+                      print(f"already at {new}: {path_str}")
+                  else:
+                      print(f"unchanged (no match!): {path_str}")
+                      if required:
+                          stale_required.append(path_str)
+
+          if missing_required or stale_required:
+              if missing_required:
+                  print(f"::error::Required packaging files missing: {missing_required}")
+              if stale_required:
+                  print(f"::error::Required packaging files did not match any version pattern and are not at {new}: {stale_required}")
+              sys.exit(1)
           PY
 
       - name: Show diff
diff --git a/snap/snapcraft.yaml b/snap/snapcraft.yaml
index b5d3799..5c4f6b3 100644
--- a/snap/snapcraft.yaml
+++ b/snap/snapcraft.yaml
@@ -1,7 +1,7 @@
 name: pdfapps
 title: PDFApps
 base: core22
-version: '1.13.9'
+version: '1.13.15'
 summary: Fast, offline, subscription-free PDF editor
 description: |
   PDFApps is an all-in-one PDF editor with 13 built-in tools: split, merge,
diff --git a/tests/test_release_bump_script.py b/tests/test_release_bump_script.py
new file mode 100644
index 0000000..0e4ae61
--- /dev/null
+++ b/tests/test_release_bump_script.py
@@ -0,0 +1,172 @@
+"""Regression test for the release.yml inline bump script.
+
+Confirms the snap/snapcraft.yaml freeze bug (Snap Store stuck at v1.13.9
+since the v1.13.10 release) cannot recur: even when app/constants.py has
+drifted out of sync with the packaging files, the bump script must still
+update every required target or fail loudly.
+"""
+from __future__ import annotations
+
+import re
+import subprocess
+import sys
+import textwrap
+from pathlib import Path
+
+import pytest
+import yaml
+
+
+REPO_ROOT = Path(__file__).resolve().parents[1]
+RELEASE_YML = REPO_ROOT / ".github" / "workflows" / "release.yml"
+
+
+def _extract_bump_script() -> str:
+    """Pull the inline Python heredoc out of the release workflow."""
+    text = RELEASE_YML.read_text(encoding="utf-8")
+    match = re.search(
+        r"python - <<'PY'\n(.*?)\n          PY",
+        text,
+        flags=re.DOTALL,
+    )
+    assert match, "could not locate inline bump script in release.yml"
+    body = match.group(1)
+    # Strip the leading 10-space YAML indentation.
+    return textwrap.dedent(body)
+
+
+@pytest.fixture
+def fake_repo(tmp_path: Path) -> Path:
+    """Mirror the directory layout the bump script writes to."""
+    (tmp_path / "app").mkdir()
+    (tmp_path / "app" / "constants.py").write_text(
+        'APP_VERSION = "1.13.14"\n', encoding="utf-8"
+    )
+    (tmp_path / "installer.py").write_text(
+        'APP_VERSION = "1.13.14"\n', encoding="utf-8"
+    )
+    (tmp_path / "docs").mkdir()
+    (tmp_path / "docs" / "index.html").write_text(
+        '"softwareVersion": "1.13.14"\nv1.13.14\n', encoding="utf-8"
+    )
+    (tmp_path / "docs" / "changelog.html").write_text("v1.13.14\n", encoding="utf-8")
+    (tmp_path / "snap").mkdir()
+    # Frozen one minor behind app/constants.py — this is exactly the
+    # bug we're guarding against.
+    (tmp_path / "snap" / "snapcraft.yaml").write_text(
+        "name: pdfapps\nversion: '1.13.9'\n", encoding="utf-8"
+    )
+    (tmp_path / "rpm").mkdir()
+    (tmp_path / "rpm" / "pdfapps.spec").write_text(
+        "Name:           pdfapps\nVersion:        1.13.9\n", encoding="utf-8"
+    )
+    for sub in ("pdfapps", "pdfapps-bin"):
+        (tmp_path / "aur" / sub).mkdir(parents=True)
+        (tmp_path / "aur" / sub / "PKGBUILD").write_text(
+            "pkgver=1.13.9\n", encoding="utf-8"
+        )
+    (tmp_path / "aur" / "pdfapps" / ".SRCINFO").write_text(
+        "pkgname = pdfapps\n\tpkgver = 1.13.9\n\tsource = pdfapps-1.13.9.tar.gz::"
+        "https://github.com/x/x/archive/v1.13.9.tar.gz\n",
+        encoding="utf-8",
+    )
+    (tmp_path / "aur" / "pdfapps-bin" / ".SRCINFO").write_text(
+        "pkgname = pdfapps-bin\n\tpkgver = 1.13.10\n\tprovides = pdfapps=1.13.10\n"
+        "\tsource = pdfapps-1.13.10.tar.gz::https://x/v1.13.10/y.tar.gz\n",
+        encoding="utf-8",
+    )
+    (tmp_path / "winget").mkdir()
+    (tmp_path / "winget" / "nelsonduarte.PDFApps.installer.yaml").write_text(
+        "PackageVersion: 1.13.9\nInstallerUrl: https://x/v1.13.9/y.exe\n",
+        encoding="utf-8",
+    )
+    (tmp_path / "winget" / "nelsonduarte.PDFApps.locale.en-US.yaml").write_text(
+        "PackageVersion: 1.13.9\nReleaseNotesUrl: https://x/v1.13.9\n",
+        encoding="utf-8",
+    )
+    (tmp_path / "winget" / "nelsonduarte.PDFApps.yaml").write_text(
+        "PackageVersion: 1.13.9\n", encoding="utf-8"
+    )
+    (tmp_path / "flatpak").mkdir()
+    (tmp_path / "flatpak" / "io.github.nelsonduarte.PDFApps.yml").write_text(
+        "    sources:\n      - type: git\n        tag: v1.13.9\n",
+        encoding="utf-8",
+    )
+    return tmp_path
+
+
+def _run_script(repo: Path, *, old: str, new: str) -> subprocess.CompletedProcess[str]:
+    script = _extract_bump_script()
+    return subprocess.run(
+        [sys.executable, "-c", script],
+        cwd=repo,
+        env={"OLD": old, "PATH": "", "NEW": new, "SYSTEMROOT": __import__("os").environ.get("SYSTEMROOT", "")},
+        capture_output=True,
+        text=True,
+    )
+
+
+def test_bump_script_updates_snap_even_when_constants_drifted(fake_repo: Path) -> None:
+    """The exact failure mode that froze the Snap Store at 1.13.9."""
+    result = _run_script(fake_repo, old="1.13.14", new="1.13.15")
+    assert result.returncode == 0, f"bump failed:\nstdout={result.stdout}\nstderr={result.stderr}"
+
+    snap = yaml.safe_load((fake_repo / "snap" / "snapcraft.yaml").read_text())
+    assert snap["version"] == "1.13.15", (
+        "snapcraft.yaml must move to the new version even though "
+        "the OLD value from constants.py never appeared in it"
+    )
+
+
+def test_bump_script_updates_all_required_packaging_files(fake_repo: Path) -> None:
+    result = _run_script(fake_repo, old="1.13.14", new="1.13.15")
+    assert result.returncode == 0, result.stderr
+
+    # Spot-check each ecosystem.
+    assert 'APP_VERSION = "1.13.15"' in (fake_repo / "app" / "constants.py").read_text()
+    assert "Version:        1.13.15" in (fake_repo / "rpm" / "pdfapps.spec").read_text()
+    assert "pkgver=1.13.15" in (fake_repo / "aur" / "pdfapps" / "PKGBUILD").read_text()
+    assert "pkgver=1.13.15" in (fake_repo / "aur" / "pdfapps-bin" / "PKGBUILD").read_text()
+    assert "PackageVersion: 1.13.15" in (
+        fake_repo / "winget" / "nelsonduarte.PDFApps.installer.yaml"
+    ).read_text()
+    assert "tag: v1.13.15" in (
+        fake_repo / "flatpak" / "io.github.nelsonduarte.PDFApps.yml"
+    ).read_text()
+    # No stale 1.13.9 / 1.13.10 / 1.13.14 references in required files.
+    for path in [
+        fake_repo / "snap" / "snapcraft.yaml",
+        fake_repo / "rpm" / "pdfapps.spec",
+        fake_repo / "aur" / "pdfapps" / "PKGBUILD",
+        fake_repo / "aur" / "pdfapps-bin" / "PKGBUILD",
+        fake_repo / "winget" / "nelsonduarte.PDFApps.installer.yaml",
+        fake_repo / "flatpak" / "io.github.nelsonduarte.PDFApps.yml",
+    ]:
+        body = path.read_text()
+        assert "1.13.9" not in body, f"{path.name} still references 1.13.9"
+        assert "1.13.10" not in body, f"{path.name} still references 1.13.10"
+        assert "1.13.14" not in body, f"{path.name} still references 1.13.14"
+
+
+def test_bump_script_is_idempotent(fake_repo: Path) -> None:
+    """Running the bump twice with the same NEW must not fail."""
+    first = _run_script(fake_repo, old="1.13.14", new="1.13.15")
+    assert first.returncode == 0, first.stderr
+    second = _run_script(fake_repo, old="1.13.15", new="1.13.15")
+    assert second.returncode == 0, (
+        f"second bump should be a no-op, got: {second.stdout}\n{second.stderr}"
+    )
+
+
+def test_current_snapcraft_yaml_is_at_release_version() -> None:
+    """Belt-and-braces guard against re-introducing the freeze."""
+    constants = (REPO_ROOT / "app" / "constants.py").read_text(encoding="utf-8")
+    match = re.search(r'APP_VERSION\s*=\s*"([^"]+)"', constants)
+    assert match, "APP_VERSION not found in app/constants.py"
+    app_version = match.group(1)
+
+    snap = yaml.safe_load((REPO_ROOT / "snap" / "snapcraft.yaml").read_text())
+    assert snap["version"] == app_version, (
+        f"snap/snapcraft.yaml version ({snap['version']!r}) is out of sync "
+        f"with app/constants.py ({app_version!r}) — Snap Store will freeze"
+    )