diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7099c93..41b6d3d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -15,6 +15,12 @@ per-file diff commands.
 
 ### Added
 
+- **Tests for `check_framework_version.py`** - the CI gate that stops a framework file
+  from being edited without a `framework_version` bump had zero tests, so the one-line
+  mutation `return meaningful_changes > 0` -> `return False` disabled it while the suite
+  stayed green. Four cases in the new `tests/test_check_framework_version.py` (clean
+  tree, unbumped edit, bumped edit, missing marker), each running the real script inside
+  an isolated git repo. Mutation-verified against that exact disable.
 - **Tests for `lint_skills.py`'s skill and command checks** - only `check_settings()`
   had coverage; the linter's main job (frontmatter keys, `allowed-tools` targets
   existing, the `# /<name>` command title rule) was unasserted, so deleting the
diff --git a/tests/test_check_framework_version.py b/tests/test_check_framework_version.py
new file mode 100644
index 0000000..9562233
--- /dev/null
+++ b/tests/test_check_framework_version.py
@@ -0,0 +1,110 @@
+"""Guards for tools/check_framework_version.py - the CI gate itself.
+
+This gate is what stops a PR from editing a profile-bearing framework
+file without bumping `framework_version` (the fork-rebase safety marker).
+It ran in CI with zero tests, so a one-line mutation
+(`return meaningful_changes > 0` -> `return False`) disabled it while
+the whole suite stayed green (review finding F22, 2026-08-19). A broken
+guard is silent by construction: nothing fails, it just stops catching.
+
+Each test builds an isolated git repo with the script copied inside it
+(the script resolves ROOT from __file__), so the real repo is never read
+or written.
+"""
+import os
+import shutil
+import subprocess
+import sys
+import tempfile
+import unittest
+from pathlib import Path
+
+REPO_ROOT = Path(__file__).resolve().parent.parent
+SCRIPT = REPO_ROOT / "tools" / "check_framework_version.py"
+
+FRONTMATTER = "---\nframework_version: 1.0.0\n---\n"
+BODY = "# Test framework file\n\nOriginal guidance sentence.\n"
+
+
+class CheckerRepoFixture(unittest.TestCase):
+    def setUp(self):
+        self.root = Path(tempfile.mkdtemp())
+        self.addCleanup(shutil.rmtree, self.root, ignore_errors=True)
+
+        tools = self.root / "tools"
+        tools.mkdir()
+        shutil.copy(SCRIPT, tools / "check_framework_version.py")
+
+        self.skill_dir = self.root / ".claude" / "skills" / "job-application-assistant"
+        self.skill_dir.mkdir(parents=True)
+        self.framework_file = self.skill_dir / "01-test-profile.md"
+        self.framework_file.write_text(FRONTMATTER + BODY, encoding="utf-8")
+
+        self.git("init", "-q")
+        self.git("add", "-A")
+        self.git("commit", "-q", "-m", "base")
+
+    def git(self, *args):
+        subprocess.run(
+            ["git", "-c", "user.name=test", "-c", "user.email=test@example.com", *args],
+            cwd=self.root,
+            check=True,
+            capture_output=True,
+            text=True,
+        )
+
+    def run_checker(self):
+        # Strip GitHub Actions variables so get_base_commit() takes the
+        # local path (uncommitted changes vs HEAD) regardless of where the
+        # test suite itself runs.
+        env = {k: v for k, v in os.environ.items() if not k.startswith("GITHUB_")}
+        return subprocess.run(
+            [sys.executable, str(self.root / "tools" / "check_framework_version.py")],
+            capture_output=True,
+            text=True,
+            env=env,
+        )
+
+
+class FrameworkVersionGateTests(CheckerRepoFixture):
+    def test_clean_tree_passes(self):
+        result = self.run_checker()
+
+        self.assertEqual(result.returncode, 0, result.stdout + result.stderr)
+        self.assertIn("Framework Version Check: OK", result.stdout)
+
+    def test_unbumped_edit_fails(self):
+        self.framework_file.write_text(
+            FRONTMATTER + BODY + "\nA new sentence without a version bump.\n",
+            encoding="utf-8",
+        )
+
+        result = self.run_checker()
+
+        self.assertEqual(result.returncode, 1, result.stdout + result.stderr)
+        self.assertIn("modified without bumping 'framework_version'", result.stdout)
+
+    def test_bumped_edit_passes(self):
+        bumped = FRONTMATTER.replace("1.0.0", "1.0.1")
+        self.framework_file.write_text(
+            bumped + BODY + "\nA new sentence with a version bump.\n",
+            encoding="utf-8",
+        )
+
+        result = self.run_checker()
+
+        self.assertEqual(result.returncode, 0, result.stdout + result.stderr)
+
+    def test_file_without_version_marker_fails(self):
+        (self.skill_dir / "02-unmarked.md").write_text(
+            "# No frontmatter at all\n", encoding="utf-8"
+        )
+
+        result = self.run_checker()
+
+        self.assertEqual(result.returncode, 1, result.stdout + result.stderr)
+        self.assertIn("missing 'framework_version'", result.stdout)
+
+
+if __name__ == "__main__":
+    unittest.main()