diff --git a/src/backend/modern.lisp b/src/backend/modern.lisp
index 17254a7..a87fd30 100644
--- a/src/backend/modern.lisp
+++ b/src/backend/modern.lisp
@@ -174,9 +174,11 @@ as a fallback when a keyword is not in *named-colors*.")
                          (sb-alien:deref winsize 0))) ;; rows
             (sb-alien:free-alien winsize))))
       ;; stty size via subprocess — reliable on every Unix, bypasses
-      ;; SBCL's alien/ioctl quirks. Returns "ROWS COLS".
+      ;; SBCL's alien/ioctl quirks. Returns "ROWS COLS".  Use sh -c
+      ;; with explicit /dev/tty to ensure stty sees the real terminal
+      ;; (uiop:run-program may redirect stdin).
       (ignore-errors
-        (let* ((out (uiop:run-program '("stty" "size")
+        (let* ((out (uiop:run-program '("sh" "-c" "stty size < /dev/tty")
                                       :output :string
                                       :ignore-error-status t))
                (parts (and out (uiop:split-string
diff --git a/src/backend/simple.lisp b/src/backend/simple.lisp
index 9b1f479..52bdce1 100644
--- a/src/backend/simple.lisp
+++ b/src/backend/simple.lisp
@@ -36,7 +36,7 @@
              (sb-alien:free-alien winsize))))
       ;; stty size via subprocess — reliable on every Unix.
       (ignore-errors
-        (let* ((out (uiop:run-program '("stty" "size")
+        (let* ((out (uiop:run-program '("sh" "-c" "stty size < /dev/tty")
                                       :output :string
                                       :ignore-error-status t))
                (parts (and out (uiop:split-string