diff --git a/lib/tcl/conformance.sh b/lib/tcl/conformance.sh
index 23ce41fb..b6f057e4 100755
--- a/lib/tcl/conformance.sh
+++ b/lib/tcl/conformance.sh
@@ -69,6 +69,7 @@ for tcl_file in "${TCL_FILES[@]}"; do
 (epoch 2)
 (load "lib/tcl/parser.sx")
 (epoch 3)
+(load "lib/guest/reflective/env.sx")
 (load "lib/tcl/runtime.sx")
 (epoch 4)
 (load "$helper")
diff --git a/lib/tcl/runtime.sx b/lib/tcl/runtime.sx
index 4bb268af..7c761c51 100644
--- a/lib/tcl/runtime.sx
+++ b/lib/tcl/runtime.sx
@@ -1,25 +1,33 @@
 ; Tcl-on-SX runtime evaluator
 ; State: {:frame frame :commands cmd-table :result last-result :output accumulated-output}
-; Requires lib/fiber.sx to be loaded first (provides make-fiber, fiber-resume, fiber-done?)
+; Requires lib/fiber.sx and lib/guest/reflective/env.sx to be loaded first.
+;
+; Frames keep their Tcl-specific shape ({:level :locals :parent}) but
+; route lookup/bind through the shared reflective env kit via the
+; adapter cfg below — second consumer for that kit alongside Kernel.
 
 (define make-frame (fn (level parent) {:level level :locals {} :parent parent}))
 
-(define
-  frame-lookup
-  (fn
-    (frame name)
-    (if
-      (nil? frame)
-      nil
-      (let
-        ((val (get (get frame :locals) name)))
-        (if (nil? val) (frame-lookup (get frame :parent) name) val)))))
+; Tcl-side adapter for lib/guest/reflective/env.sx. Frames are
+; functionally updated (assoc returns a fresh dict), and lookup-miss
+; returns nil (Tcl convention) — the *-with kit honours both.
+(define tcl-frame-cfg
+  {:bindings-of (fn (f) (get f :locals))
+   :parent-of   (fn (f) (get f :parent))
+   :extend      (fn (f) (make-frame (+ (get f :level) 1) f))
+   :bind!       (fn (f n v) (assoc f :locals (assoc (get f :locals) n v)))
+   :env?        (fn (v)
+                  (and (dict? v)
+                       (number? (get v :level))
+                       (dict? (get v :locals))))})
 
-(define
-  frame-set-top
-  (fn
-    (frame name val)
-    (assoc frame :locals (assoc (get frame :locals) name val))))
+(define frame-lookup
+  (fn (frame name)
+    (refl-env-lookup-or-nil-with tcl-frame-cfg frame name)))
+
+(define frame-set-top
+  (fn (frame name val)
+    (refl-env-bind!-with tcl-frame-cfg frame name val)))
 
 (define make-tcl-interp (fn () {:result "" :output "" :code 0 :errorinfo "" :errorcode "" :frame (make-frame 0 nil) :frame-stack (list) :procs {} :commands {} :current-ns "::" :coro-yield-fn nil}))
 
diff --git a/lib/tcl/test.sh b/lib/tcl/test.sh
index 3bf15b1f..667b8181 100755
--- a/lib/tcl/test.sh
+++ b/lib/tcl/test.sh
@@ -42,6 +42,7 @@ cat > "$TMPFILE" << EPOCHS
 (load "lib/tcl/tests/parse.sx")
 (epoch 4)
 (load "lib/fiber.sx")
+(load "lib/guest/reflective/env.sx")
 (load "lib/tcl/runtime.sx")
 (epoch 5)
 (load "lib/tcl/tests/eval.sx")