diff --git a/org/channel-tui-view.org b/org/channel-tui-view.org
index 97daf45..a7254a1 100644
--- a/org/channel-tui-view.org
+++ b/org/channel-tui-view.org
@@ -59,7 +59,9 @@ Returns a list of strings, one per line."
     (nreverse lines)))
 
 (defun view-status (fb w h)
-  (let* ((bg (theme-color :status-bg))
+  (let* ((w (or (and (numberp w) (> w 0) w) 80))
+         (h (or (and (numberp h) (> h 0) h) 24))
+         (bg (theme-color :status-bg))
          (fg (theme-color :status-fg))
          (ver (st :daemon-version))
          (ver-str (if ver (format nil " v~a" ver) ""))
@@ -94,7 +96,9 @@ Returns a list of strings, one per line."
       (if (string= result "") content result))))
 
 (defun view-chat (fb w h)
-  (let* ((msgs (st :messages)) (total (length msgs))
+  (let* ((w (or (and (numberp w) (> w 0) w) 80))
+         (h (or (and (numberp h) (> h 0) h) 24))
+         (msgs (st :messages)) (total (length msgs))
          (max-lines (- h 4)) (is-search (st :search-mode)) (y 0))
     (when is-search
       (let* ((matches (st :search-matches)) (idx (st :search-match-idx))
@@ -209,7 +213,9 @@ Returns a list of strings, one per line."
 ** Input Line
 #+BEGIN_SRC lisp :tangle /home/user/.local/share/passepartout/lisp/channel-tui-view.lisp
 (defun view-input (fb w h)
-  (let* ((text (input-string))
+  (let* ((w (or (and (numberp w) (> w 0) w) 80))
+         (h (or (and (numberp h) (> h 0) h) 24))
+         (text (input-string))
          (pos (or (st :cursor-pos) 0))
          (display-start (max 0 (- pos (1- w))))
          (visible (subseq text display-start (min (length text) (+ display-start w)))))
@@ -222,7 +228,9 @@ Returns a list of strings, one per line."
 #+BEGIN_SRC lisp :tangle /home/user/.local/share/passepartout/lisp/channel-tui-view.lisp
 (defun view-sidebar (fb w h)
   "Render the right-side sidebar panel with warm colors."
-  (let* ((x (- w (or (st :sidebar-width) 30)))
+  (let* ((w (or (and (numberp w) (> w 0) w) 80))
+         (h (or (and (numberp h) (> h 0) h) 24))
+         (x (- w (or (st :sidebar-width) 30)))
          (y 0))
     ;; Vertical separator
     (dotimes (row h)
@@ -266,6 +274,8 @@ Returns a list of strings, one per line."
 ** Redraw (dirty-flag dispatch)
 #+begin_src lisp
 (defun redraw (fb w h)
+  (setq w (or (and (numberp w) (> w 0) w) 80)
+        h (or (and (numberp h) (> h 0) h) 24))
   (destructuring-bind (sd cd id) (st :dirty)
     (when sd (view-status fb w h))
     (when cd (view-chat fb w h))
diff --git a/passepartout b/passepartout
index 9ea8b42..f233c4d 100755
--- a/passepartout
+++ b/passepartout
@@ -406,9 +406,12 @@ case "$COMMAND" in
   (sleep 3) (finish-output) (uiop:quit 1))))
   (passepartout.channel-tui:tui-main))
 LISPEOF
-        # Export terminal dimensions — bash sets COLUMNS/LINES but
-        # doesn't export them to subprocesses by default.
-        export COLUMNS LINES
+        # Set terminal dimensions from stty — bash's $COLUMNS/$LINES
+        # are often missing or not exported. stty size always works.
+        local ts=$(stty size 2>/dev/null)
+        export COLUMNS="${ts#* }" LINES="${ts% *}"
+        [ -z "$COLUMNS" ] && COLUMNS=80
+        [ -z "$LINES" ] && LINES=24
         # Clear stale cl-tty cache to ensure latest backend-size fixes
         find ~/.cache/common-lisp -name "*.fasl" -path "*cl-tty*" -delete 2>/dev/null
         exec sbcl --noinform --load /tmp/tui-load.lisp