diff --git a/plans/agent-briefings/sx-gate-loop.md b/plans/agent-briefings/sx-gate-loop.md
index a4b2adb8..06efb551 100644
--- a/plans/agent-briefings/sx-gate-loop.md
+++ b/plans/agent-briefings/sx-gate-loop.md
@@ -98,13 +98,28 @@ Pin each confirmed-and-fixed finding with a minimal repro. Add suites to
       (`scripts/test-suite-baseline.sh` + `spec/tests/known-failures.txt`,
       273 pinned: 271 hs-* + 2 empty-suite-label entries → C9 evidence).
       New failure OR vanished failure = red; hs loops' scoreboards untouched
-- [ ] C9 — empty suite label
+- [x] C9 — empty suite labels ELIMINATED: 6 files had suite-less top-level
+      deftests (chars 43, import-bind 14, ports 12, let-match 8, math
+      nested-deftests, 4 hs strays) — wrapped/restructured into defsuites;
+      baseline identities updated in the same commit
 
 ### F. Differential battery
 - [ ] F8 — cross-host differential battery (same source, all hosts agree)
 
 ## Progress log (newest first)
 
+- 2026-07-04 — **C9 empty-suite labels (item E.3) — section E COMPLETE**.
+  The sweep found the defect much wider than the finding: SIX files carried
+  suite-less top-level deftests (test-chars 43, test-import-bind 14,
+  test-ports 12, test-let-match 8, test-math as deftest-nested-in-deftest,
+  test-hyperscript-conformance 4 strays between suites). Fixes: file-level
+  defsuite wraps (validated via sx_validate after mechanical wrap),
+  test-math restructured deftest→defsuite (labels now "math > sin"),
+  hs strays wrapped in section-comment-named suites (hs-compat-
+  blockLiteral/cookies/some/where). The two baseline-visible identities
+  renamed in known-failures.txt in the SAME commit. Full-gate validated
+  GREEN (5798p/273f — −2 passes are the wrapper deftests that no longer
+  self-report; fail set byte-identical). Test-only.
 - 2026-07-04 — **F10 baseline gate (item E.2)**. Deliberately NOT a
   skip-list: skip-listing the hs red band in the runner would rewrite the
   hs loops' scoreboards mid-flight. Instead
diff --git a/spec/tests/known-failures.txt b/spec/tests/known-failures.txt
index edcbfcf0..59bcc774 100644
--- a/spec/tests/known-failures.txt
+++ b/spec/tests/known-failures.txt
@@ -1,7 +1,7 @@
- > can-map-an-array
 hs-compat-asExpression > converts-a-complete-form-into-values
 hs-compat-asExpression > converts-strings-into-fragments
 hs-compat-asExpression > converts-value-as-json
+hs-compat-blockLiteral > can-map-an-array
 hs-compat-in > basic-no-query-return-values
 hs-compat-typecheck > can-do-basic-non-string-typecheck-failure
 hs-compat-typecheck > can-do-basic-string-non-null-typecheck
@@ -270,4 +270,4 @@ hs-upstream-wait > can wait on event
 hs-upstream-wait > can wait on event on another element
 hs-upstream-wait > waiting on an event sets 'it' to the event
 hs-upstream-when > attribute observers are persistent (not recreated on re-run)
- > string->number
+math > string->number
diff --git a/spec/tests/test-chars.sx b/spec/tests/test-chars.sx
index b94b9aa7..81ce58eb 100644
--- a/spec/tests/test-chars.sx
+++ b/spec/tests/test-chars.sx
@@ -1,3 +1,5 @@
+(defsuite "chars"
+
 ;; Tests for character type (Phase 13)
 ;; Uses (make-char n) and (char-code "x") instead of #\x literals
 ;; (char literal parser syntax tested via sx-parse call)
@@ -183,3 +185,5 @@
 (deftest
   "char-ci>=? equal case-insensitive"
   (assert= true (char-ci>=? (make-char 97) (make-char 65))))
+
+)
diff --git a/spec/tests/test-hyperscript-conformance.sx b/spec/tests/test-hyperscript-conformance.sx
index 015905e7..7e2350eb 100644
--- a/spec/tests/test-hyperscript-conformance.sx
+++ b/spec/tests/test-hyperscript-conformance.sx
@@ -180,11 +180,12 @@
   (deftest "converts-foo-bar" (for-each run-hs-fixture (list {:src "1 as String" :expected "1"}))))
 
 ;; ── blockLiteral (4 fixtures) ──────────────────────────────
+(defsuite "hs-compat-blockLiteral"
 (deftest
   "can-map-an-array"
   (let
     ((r (eval-hs "['a', 'ab', 'abc'].map(\\ s -> s.length)")))
-    (assert= r (list 1 2 3) "map with block")))
+    (assert= r (list 1 2 3) "map with block"))))
 
 ;; ── boolean (2 fixtures) ──────────────────────────────
 (defsuite
@@ -325,9 +326,10 @@
     (for-each run-hs-fixture (list {:src "undefined does not exist" :expected true} {:src "null does not exist" :expected true}))))
 
 ;; ── cookies (9 fixtures) ──────────────────────────────
+(defsuite "hs-compat-cookies"
 (deftest
   "update-cookie-values-work"
-  (for-each run-hs-fixture (list {:src "cookies.foo" :locals {:cookies {:foo "doh"}} :expected "doh"})))
+  (for-each run-hs-fixture (list {:src "cookies.foo" :locals {:cookies {:foo "doh"}} :expected "doh"}))))
 
 ;; ── in (4 fixtures) ──────────────────────────────
 (defsuite
@@ -464,9 +466,10 @@
       (assert= (len r) 0 "empty query result"))))
 
 ;; ── some (6 fixtures) ──────────────────────────────
+(defsuite "hs-compat-some"
 (deftest
   "some-returns-true-for-nonempty-selector"
-  (for-each run-hs-fixture (list {:src "some [1]" :expected true})))
+  (for-each run-hs-fixture (list {:src "some [1]" :expected true}))))
 
 ;; ── stringPostfix (10 fixtures) ──────────────────────────────
 (defsuite
@@ -695,13 +698,14 @@
   (deftest "null-not-exist" (for-each run-hs-fixture (list {:src "null does not exist" :expected true})))
   (deftest "undef-not-exist" (for-each run-hs-fixture (list {:src "undefined does not exist" :locals {:undefined nil} :expected true}))))
 
+(defsuite "hs-compat-where"
 (deftest
   "where-with-property"
   (let
     ((items (list {:age 15 :name "Alice"} {:age 30 :name "Bob"})))
     (let
       ((r (eval-hs "items where its age > 20" {:locals {:items items}})))
-      (assert= (len r) 1 "one match"))))
+      (assert= (len r) 1 "one match")))))
 
 (defsuite
   "hs-0990-collection-ops"
diff --git a/spec/tests/test-import-bind.sx b/spec/tests/test-import-bind.sx
index f65b74c4..19eaaba0 100644
--- a/spec/tests/test-import-bind.sx
+++ b/spec/tests/test-import-bind.sx
@@ -1,3 +1,5 @@
+(defsuite "import-bind"
+
 ;; Tests for define-library, import, and the import suspension mechanism
 
 ;; ============================================================
@@ -190,3 +192,5 @@
   (assert=
     (cek-try (fn () inner-secret) (fn (e) "not-found"))
     "not-found"))
+
+)
diff --git a/spec/tests/test-let-match.sx b/spec/tests/test-let-match.sx
index 5919f80c..27c2f846 100644
--- a/spec/tests/test-let-match.sx
+++ b/spec/tests/test-let-match.sx
@@ -1,3 +1,5 @@
+(defsuite "let-match"
+
 ;; Tests for let-match — CEK special form and bytecode compiler desugaring
 ;; let-match destructures a dict: (let-match {:key var} expr body...)
 
@@ -45,3 +47,5 @@
   (let-match {:a a :b b} (dict :a (+ 1 2) :b (* 3 4))
     (assert= a 3)
     (assert= b 12)))
+
+)
diff --git a/spec/tests/test-math.sx b/spec/tests/test-math.sx
index 415d38b4..70d5377b 100644
--- a/spec/tests/test-math.sx
+++ b/spec/tests/test-math.sx
@@ -1,7 +1,10 @@
+;; Math completeness tests. C9 note: this file used NESTED deftests with no
+;; defsuite, so every test reported with an empty suite label (" > sin").
+;; Restructured to defsuite/deftest — labels are now "math > sin" etc.
 
-(deftest
-  "math completeness"
-  (deftest
+(defsuite
+  "math"
+  (defsuite
     "trigonometry"
     (deftest
       "sin"
@@ -124,7 +127,10 @@
       true
       (< (abs (- (cos (acos 0.5)) 0.5)) 0.0001)
       "cos(acos(x)) = x")
-    (assert= true (< (abs (- (exp (log 2)) 2)) 0.0001) "exp(log(x)) = x")
+    (assert=
+      true
+      (< (abs (- (exp (log 2)) 2)) 0.0001)
+      "exp(log(x)) = x")
     (assert=
       (* 12 18)
       (* (gcd 12 18) (lcm 12 18))
diff --git a/spec/tests/test-ports.sx b/spec/tests/test-ports.sx
index a4426d45..aff0d2ce 100644
--- a/spec/tests/test-ports.sx
+++ b/spec/tests/test-ports.sx
@@ -1,3 +1,5 @@
+(defsuite "ports"
+
 ;; Phase 14 — String ports + eof-object
 
 (deftest
@@ -230,3 +232,5 @@
           (c3 (read-char in))
           (when (not (eof-object? c3)) (write-char c3 out)))
         (assert= "abc" (get-output-string out) "roundtrip via ports")))))
+
+)