diff --git a/bin/gstack-retro-metrics b/bin/gstack-retro-metrics
index 58c2c05180..4f9b5b219e 100755
--- a/bin/gstack-retro-metrics
+++ b/bin/gstack-retro-metrics
@@ -297,10 +297,14 @@ echo "PRS_REFERENCED: $(printf '%s' "$_PRS" | wc -w | tr -d ' ')"
 [ -n "$_PRS" ] && echo "PR_REFS: $_PRS" || true
 
 # ── Test health (repo-wide + window) ─────────────────────────────────────────
-# Deliberately suffix-only (narrower than is_test's dir-based patterns): the
-# repo-wide census counts conventional test FILES; is_test additionally counts
-# dir-homed helpers toward test-insertion ratios.
-_TF_TOTAL=$(git ls-files 2>/dev/null | grep -cE '(\.test\.|\.spec\.|_test\.|_spec\.)' || true)
+# Deliberately filename-convention-only (narrower than is_test's dir-based
+# patterns): the repo-wide census counts conventional test FILES; is_test
+# additionally counts dir-homed helpers toward test-insertion ratios.
+# Suffix forms cover JS/TS (.test./.spec.), Go (_test.), Ruby (_spec.).
+# The trailing prefix form covers pytest/unittest and minitest, whose default
+# discovery is `test_*.py` / `test_*.rb` -- a filename convention, not a
+# directory one, so it does not readmit dir-homed helpers like tests/utils.py.
+_TF_TOTAL=$(git ls-files 2>/dev/null | grep -cE '(\.test\.|\.spec\.|_test\.|_spec\.|(^|/)test_[^/]*\.(py|rb)$)' || true)
 case "$_TF_TOTAL" in ''|*[!0-9]*) _TF_TOTAL=0 ;; esac
 echo "TEST_FILES_TOTAL: $_TF_TOTAL"
 _REG=$(git log "$REF" "$_S" ${_U:+"$_U"} --oneline --grep="test(qa):" --grep="test(design):" --grep="test: coverage" 2>/dev/null || true)
diff --git a/test/gstack-retro-metrics.test.ts b/test/gstack-retro-metrics.test.ts
index c1cf2450cf..10018b2251 100644
--- a/test/gstack-retro-metrics.test.ts
+++ b/test/gstack-retro-metrics.test.ts
@@ -306,6 +306,37 @@ describe('gstack-retro-metrics edges', () => {
     }
   });
 
+  // Regression: the repo-wide census was suffix-only, so pytest/unittest's
+  // default `test_*.py` discovery name counted as zero. A Python repo whose
+  // whole suite is `tests/test_*.py` reported TEST_FILES_TOTAL: 0 while its
+  // TEST_RATIO was healthy -- the two lines disagreed and the low one was
+  // silently wrong. Dir-homed helpers (tests/utils.py) must still NOT count.
+  test('counts pytest-style test_*.py and minitest test_*.rb, not dir-homed helpers', () => {
+    const pyDir = fs.mkdtempSync(path.join(os.tmpdir(), 'gstack-rm-py-'));
+    try {
+      git(pyDir, ['init', '-b', 'main']);
+      git(pyDir, ['config', 'user.email', 'py@example.com']);
+      git(pyDir, ['config', 'user.name', 'Py']);
+      fs.mkdirSync(path.join(pyDir, 'tests'), { recursive: true });
+      fs.mkdirSync(path.join(pyDir, 'app'), { recursive: true });
+      write(pyDir, 'tests/test_login.py', 'def test_login():\n    assert True\n');
+      write(pyDir, 'tests/test_logout.py', 'def test_logout():\n    assert True\n');
+      write(pyDir, 'tests/helper_test.rb', "require 'minitest'\n");
+      write(pyDir, 'tests/test_signup.rb', "require 'minitest'\n");
+      // Must NOT count: a dir-homed helper, and a source file merely prefixed
+      // with "test" but not "test_".
+      write(pyDir, 'tests/utils.py', 'HELPER = 1\n');
+      write(pyDir, 'app/testing.py', 'MODE = 1\n');
+      commit(pyDir, 'test: add suite', '2026-03-10T09:00:00');
+      const out = runMetrics(['--base', 'main', '--since', '2026-03-09T00:00:00'], pyDir);
+      // test_login.py, test_logout.py, test_signup.rb (prefix) + helper_test.rb (suffix) = 4
+      expect(out).toMatch(/^TEST_FILES_TOTAL: 4$/m);
+      expect(out).toMatch(/^RETRO_METRICS_END: ok$/m);
+    } finally {
+      fs.rmSync(pyDir, { recursive: true, force: true });
+    }
+  });
+
   test('local reads only: no network git ops or curl anywhere in the script', () => {
     const script = fs.readFileSync(SCRIPT, 'utf-8');
     expect(script).not.toMatch(/(^|[;|&`($!]|\s)git(\s+-C\s+\S+)?\s+(push|pull|fetch|clone|ls-remote)\b/m);