diff --git a/host/chez/compile-eval.ss b/host/chez/compile-eval.ss
index 1b4f3d1..720b944 100644
--- a/host/chez/compile-eval.ss
+++ b/host/chez/compile-eval.ss
@@ -108,11 +108,15 @@
 ;; visible (macro flag set, var interned) before a later subform is analyzed.
 (define (jolt-compile-eval-form form ns)
   (cond
+    ;; thread the current ns: an earlier subform may switch it (ns/in-ns call
+    ;; set-chez-ns!), and the next subform must be ANALYZED in that ns so its defs
+    ;; land there and its refs resolve (cross-ns def/require in one program).
     ((ce-top-do? form)
-     (let loop ((fs (cdr (seq->list form))) (result jolt-nil))
+     (let loop ((fs (cdr (seq->list form))) (result jolt-nil) (cur ns))
        (if (null? fs)
            result
-           (loop (cdr fs) (jolt-compile-eval-form (car fs) ns)))))
+           (let ((r (jolt-compile-eval-form (car fs) cur)))
+             (loop (cdr fs) r (chez-current-ns))))))
     ;; runtime defmacro: def the expander fn + mark the var a macro so subsequent
     ;; forms expand it (hc-macro? reads var-macro-table). Mirrors emit-image.ss
     ;; ei-emit-ns.
diff --git a/host/chez/multimethods.ss b/host/chez/multimethods.ss
index 2aa5660..4af26e3 100644
--- a/host/chez/multimethods.ss
+++ b/host/chez/multimethods.ss
@@ -56,11 +56,16 @@
 ;; if absent (defmethod before defmulti — rare; identity dispatch as a fallback).
 (define (jolt-defmethod-setup mm-sym dval impl)
   (let* ((nm (symbol-t-name mm-sym))
-         (cur (var-deref (chez-current-ns) nm))
+         ;; a QUALIFIED multifn (cf.mm/ext) resolves in its own ns (cross-ns
+         ;; defmethod), not the current one — else we'd auto-create a stray multifn.
+         (sns (symbol-t-ns mm-sym))
+         (qns (and sns (not (jolt-nil? sns)) (not (null? sns)) sns))
+         (mns (if qns (or (chez-resolve-alias (chez-current-ns) qns) qns) (chez-current-ns)))
+         (cur (var-deref mns nm))
          (mf (if (jolt-multifn? cur) cur
                  (let ((m (make-jolt-multifn nm (var-deref "clojure.core" "identity")
                                              (new-mm-table) kw-default #f (new-mm-table))))
-                   (def-var! (chez-current-ns) nm m) m))))
+                   (def-var! mns nm m) m))))
     (hashtable-set! (jolt-multifn-methods mf) dval impl)
     mf))
 
diff --git a/host/chez/natives-str.ss b/host/chez/natives-str.ss
index a108e12..d359010 100644
--- a/host/chez/natives-str.ss
+++ b/host/chez/natives-str.ss
@@ -286,4 +286,24 @@
   (for-each (lambda (s) (chez-register-spec! (chez-current-ns) s)) specs)
   jolt-nil)
 (def-var! "clojure.core" "require" chez-runtime-require)
-(def-var! "clojure.core" "use" chez-runtime-require)
+;; use = require + refer ALL of the target's public vars (unless an explicit
+;; :only/:refer filter is given, which chez-register-spec! handles per-name).
+(define (chez-runtime-use . specs)
+  (for-each
+    (lambda (spec)
+      (chez-register-spec! (chez-current-ns) spec)
+      (let* ((items (cond ((pvec? spec) (seq->list spec))
+                          ((or (cseq? spec) (empty-list-t? spec)) (seq->list spec))
+                          ((symbol-t? spec) (list spec))
+                          (else '())))
+             (target (and (pair? items) (symbol-t? (car items)) (symbol-t-name (car items))))
+             (filtered (let scan ((xs (if (pair? items) (cdr items) '())))
+                         (cond ((null? xs) #f)
+                               ((and (keyword? (car xs))
+                                     (member (keyword-t-name (car xs)) '("only" "refer"))) #t)
+                               (else (scan (cdr xs)))))))
+        (when (and target (not filtered))
+          (chez-register-refer-all! (chez-current-ns) target))))
+    specs)
+  jolt-nil)
+(def-var! "clojure.core" "use" chez-runtime-use)
diff --git a/host/chez/ns.ss b/host/chez/ns.ss
index f0751b0..40dd2b3 100644
--- a/host/chez/ns.ss
+++ b/host/chez/ns.ss
@@ -38,8 +38,19 @@
 (define ns-refer-table (make-hashtable equal-hash equal?))
 (define (chez-register-refer! cns name target)
   (hashtable-set! ns-refer-table (cons cns name) target))
+;; refer-all (a bare `use`): cns -> list of fully-referred target ns names. A name
+;; not found per-name resolves to the first refer-all target that defines it.
+(define ns-refer-all-table (make-hashtable equal-hash equal?))
+(define (chez-register-refer-all! cns target)
+  (let ((cur (hashtable-ref ns-refer-all-table cns '())))
+    (unless (member target cur)
+      (hashtable-set! ns-refer-all-table cns (cons target cur)))))
 (define (chez-resolve-refer cns name)
-  (hashtable-ref ns-refer-table (cons cns name) #f))
+  (or (hashtable-ref ns-refer-table (cons cns name) #f)
+      (let loop ((ts (hashtable-ref ns-refer-all-table cns '())))
+        (cond ((null? ts) #f)
+              ((let ((c (var-cell-lookup (car ts) name))) (and c (var-cell-defined? c))) (car ts))
+              (else (loop (cdr ts)))))))
 ;; parse a require/use spec FORM and register its :as alias + :refer names under
 ;; `cns`. spec: [ns :as a :refer [x y] ...] / (ns ...) / bare ns. opts are
 ;; keyword/value pairs after the ns symbol.
diff --git a/host/chez/run-corpus.ss b/host/chez/run-corpus.ss
index c51ddb7..0c97938 100644
--- a/host/chez/run-corpus.ss
+++ b/host/chez/run-corpus.ss
@@ -11,7 +11,7 @@
 ;; reset between cases so there is no leakage — same isolation a fresh process gives.
 ;;
 ;;   chez --script host/chez/run-corpus.ss
-;;   JOLT_CHEZ_ZJ_FLOOR=N   override the regression floor (default 2684)
+;;   JOLT_CHEZ_ZJ_FLOOR=N   override the regression floor (default 2688)
 ;;   JOLT_CORPUS_LIMIT=N    every-Nth stride (fast iteration; floor drops to 0)
 ;;   JOLT_DUMP_CRASH_LABELS=1   list crash + allowlisted labels
 (import (chezscheme))
@@ -65,6 +65,7 @@
   (zj-prune! type-registry zj-type-base)
   (hashtable-clear! ns-alias-table)
   (hashtable-clear! ns-refer-table)
+  (hashtable-clear! ns-refer-all-table)
   (when zj-ghier (jolt-invoke (var-deref "clojure.core" "reset!")
                    (var-cell-root zj-ghier) (jolt-invoke (var-deref "clojure.core" "make-hierarchy"))))
   (set-chez-ns! "user"))
@@ -202,7 +203,7 @@
 
 ;; Regression floor: fail on any NEW divergence or if pass drops below the floor.
 (define base-floor (let ((s (getenv "JOLT_CHEZ_ZJ_FLOOR")))
-                     (if s (string->number s) 2684)))
+                     (if s (string->number s) 2688)))
 (define floor (if limit 0 base-floor))
 (when (or (> (length diverged) 0) (< pass floor))
   (printf "REGRESSION: pass ~a < floor ~a or ~a new divergence(s)\n"
diff --git a/host/chez/run-unit.ss b/host/chez/run-unit.ss
index b87b668..d57b831 100644
--- a/host/chez/run-unit.ss
+++ b/host/chez/run-unit.ss
@@ -55,6 +55,7 @@
   (zj-prune! type-registry zj-type-base)
   (hashtable-clear! ns-alias-table)
   (hashtable-clear! ns-refer-table)
+  (hashtable-clear! ns-refer-all-table)
   (when zj-ghier (jolt-invoke (var-deref "clojure.core" "reset!")
                    (var-cell-root zj-ghier) (jolt-invoke (var-deref "clojure.core" "make-hierarchy"))))
   (set-chez-ns! "user"))