diff --git a/host/chez/host-static.ss b/host/chez/host-static.ss
index 369bae5..2e6deeb 100644
--- a/host/chez/host-static.ss
+++ b/host/chez/host-static.ss
@@ -94,8 +94,18 @@
 
 (define (host-new class . args)
   (let ((ctor (lookup-class class-ctors-tbl class)))
-    (if ctor (apply ctor args)
-        (error #f (string-append "No constructor for class " class)))))
+    (cond
+      (ctor (apply ctor args))
+      ;; deftype/defrecord (jolt-499t): the type name is bound as a VAR (the
+      ;; make-deftype-ctor closure) in its defining ns, not a registered host class.
+      ;; Resolve it in the current ns / clojure.core and invoke it — so (P. args)
+      ;; works the same as the ->P factory.
+      (else
+       (let ((cell (or (var-cell-lookup (chez-current-ns) class)
+                       (var-cell-lookup "clojure.core" class))))
+         (if (and cell (var-cell-defined? cell) (procedure? (var-cell-root cell)))
+             (apply (var-cell-root cell) args)
+             (error #f (string-append "No constructor for class " class))))))))
 
 ;; ---- coercion helpers -------------------------------------------------------
 (define (->num x) (exact->inexact x))
diff --git a/test/chez/run-corpus-prelude.janet b/test/chez/run-corpus-prelude.janet
index ce718c6..2fc3070 100644
--- a/test/chez/run-corpus-prelude.janet
+++ b/test/chez/run-corpus-prelude.janet
@@ -321,9 +321,9 @@
 # match the JVM's async raciness and are allowlisted) -> 2557.
 # jolt-cf1q.7 parity batches (hash/rseq/cat/transient-as-fn + ns runtime fns +
 # runtime-require alias registration) -> 2590; arrays + reader-features/
-# macroexpand/reader-conditional/re-matcher -> 2629.
+# macroexpand/reader-conditional/re-matcher -> 2629; delay/force/realized? -> 2641.
 # Strided runs scale down.
-(def base-floor (scan-number (or (os/getenv "JOLT_CHEZ_PRELUDE_FLOOR") "2629")))
+(def base-floor (scan-number (or (os/getenv "JOLT_CHEZ_PRELUDE_FLOOR") "2641")))
 (def floor (if (os/getenv "JOLT_CORPUS_LIMIT") 0 base-floor))
 (when (or (> (length diverged) 0) (< pass floor))
   (printf "REGRESSION: pass %d < floor %d or %d new divergence(s)" pass floor (length diverged)))
diff --git a/test/chez/run-corpus-zero-janet.janet b/test/chez/run-corpus-zero-janet.janet
index c0dd21d..80fa538 100644
--- a/test/chez/run-corpus-zero-janet.janet
+++ b/test/chez/run-corpus-zero-janet.janet
@@ -215,8 +215,9 @@
 # are allowlisted) -> 2567. jolt-cf1q.7 parity batches (hash/rseq/cat/transient-as-fn
 # + ns runtime fns) -> 2600; arrays -> 2631; reader-features/reader-conditional/
 # re-matcher/macroexpand -> 2642; runtime-defmacro cases via top-level eval of
-# ACTUAL (matching certify.clj's eval-isolated) -> 2673; delay/force/realized? -> 2685.
-(def base-floor (scan-number (or (os/getenv "JOLT_CHEZ_ZJ_FLOOR") "2685")))
+# ACTUAL (matching certify.clj's eval-isolated) -> 2673; delay/force/realized? ->
+# 2685; deftype (P. args) constructor via host-new var fallback -> 2688.
+(def base-floor (scan-number (or (os/getenv "JOLT_CHEZ_ZJ_FLOOR") "2688")))
 (def floor (if (os/getenv "JOLT_CORPUS_LIMIT") 0 base-floor))
 (when (or (> (length diverged) 0) (< pass floor))
   (printf "REGRESSION: pass %d < floor %d or %d new divergence(s)" pass floor (length diverged)))