diff --git a/src/backend/modern.lisp b/src/backend/modern.lisp
index e53a2d8..d87bc28 100644
--- a/src/backend/modern.lisp
+++ b/src/backend/modern.lisp
@@ -164,27 +164,30 @@ as a fallback when a keyword is not in *named-colors*.")
   (values))
 
 (defmethod backend-size ((b modern-backend))
-  (or (ignore-errors
-        (let* ((+tiocgwinsz+ 21523)  ; 0x5413 on Linux
-               (winsize (sb-alien:make-alien sb-alien:unsigned-short 4)))
-          (unwind-protect
-               (progn
-                 (sb-unix:unix-ioctl (sb-sys:fd-stream-fd (backend-output-stream b))
-                                     +tiocgwinsz+
-                                     (sb-alien:alien-sap winsize))
-                 (values (sb-alien:deref winsize 1)  ;; cols
-                         (sb-alien:deref winsize 0))) ;; rows
-            (sb-alien:free-alien winsize))))
-      ;; $COLUMNS/$LINES fallback — some systems don't update the
-      ;; TTY size via ioctl on stdout's fd.
-      (ignore-errors
-        (let* ((cstr (sb-ext:posix-getenv "COLUMNS"))
-               (rstr (sb-ext:posix-getenv "LINES"))
-               (cols (when cstr (parse-integer cstr :junk-allowed t)))
-               (rows (when rstr (parse-integer rstr :junk-allowed t))))
-          (when (and cols rows (> cols 0) (> rows 0))
-            (values cols rows))))
-      (values 80 24)))
+  (flet ((ioctl-size (fd)
+           (let* ((+tiocgwinsz+ 21523)  ; 0x5413 on Linux
+                  (winsize (sb-alien:make-alien sb-alien:unsigned-short 4)))
+             (unwind-protect
+                  (progn
+                    (sb-unix:unix-ioctl fd +tiocgwinsz+
+                                        (sb-alien:alien-sap winsize))
+                    (values (sb-alien:deref winsize 1)  ;; cols
+                            (sb-alien:deref winsize 0))) ;; rows
+               (sb-alien:free-alien winsize)))))
+    (or ;; Try ioctl on fd 0 first (stdin — stty uses this)
+        (ignore-errors (ioctl-size 0))
+        ;; Then try the output stream's fd
+        (ignore-errors
+          (ioctl-size (sb-sys:fd-stream-fd (backend-output-stream b))))
+        ;; $COLUMNS/$LINES fallback — set by every POSIX shell
+        (ignore-errors
+          (let* ((cstr (sb-ext:posix-getenv "COLUMNS"))
+                 (rstr (sb-ext:posix-getenv "LINES"))
+                 (cols (when cstr (parse-integer cstr :junk-allowed t)))
+                 (rows (when rstr (parse-integer rstr :junk-allowed t))))
+            (when (and cols rows (> cols 0) (> rows 0))
+              (values cols rows))))
+        (values 80 24))))
 
 (defmethod backend-write ((b modern-backend) string)
   (let ((stream (backend-output-stream b)))
diff --git a/src/backend/simple.lisp b/src/backend/simple.lisp
index b0fb84a..b01ffce 100644
--- a/src/backend/simple.lisp
+++ b/src/backend/simple.lisp
@@ -27,27 +27,27 @@
   (values))
 
 (defmethod backend-size ((b simple-backend))
-  (or (ignore-errors
-        (let* ((+tiocgwinsz+ 21523)
-               (winsize (sb-alien:make-alien sb-alien:unsigned-short 4)))
-          (unwind-protect
-               (progn
-                 (sb-unix:unix-ioctl (sb-sys:fd-stream-fd
-                                      (backend-output-stream b))
-                                     +tiocgwinsz+
-                                     (sb-alien:alien-sap winsize))
-                 (values (sb-alien:deref winsize 1)
-                         (sb-alien:deref winsize 0)))
-            (sb-alien:free-alien winsize))))
-      ;; $COLUMNS/$LINES fallback
-      (ignore-errors
-        (let* ((cstr (sb-ext:posix-getenv "COLUMNS"))
-               (rstr (sb-ext:posix-getenv "LINES"))
-               (cols (when cstr (parse-integer cstr :junk-allowed t)))
-               (rows (when rstr (parse-integer rstr :junk-allowed t))))
-          (when (and cols rows (> cols 0) (> rows 0))
-            (values cols rows))))
-      (values 80 24)))
+  (flet ((ioctl-size (fd)
+           (let* ((+tiocgwinsz+ 21523)
+                  (winsize (sb-alien:make-alien sb-alien:unsigned-short 4)))
+             (unwind-protect
+                  (progn
+                    (sb-unix:unix-ioctl fd +tiocgwinsz+
+                                        (sb-alien:alien-sap winsize))
+                    (values (sb-alien:deref winsize 1)
+                            (sb-alien:deref winsize 0)))
+               (sb-alien:free-alien winsize)))))
+    (or (ignore-errors (ioctl-size 0))
+        (ignore-errors
+          (ioctl-size (sb-sys:fd-stream-fd (backend-output-stream b))))
+        (ignore-errors
+          (let* ((cstr (sb-ext:posix-getenv "COLUMNS"))
+                 (rstr (sb-ext:posix-getenv "LINES"))
+                 (cols (when cstr (parse-integer cstr :junk-allowed t)))
+                 (rows (when rstr (parse-integer rstr :junk-allowed t))))
+            (when (and cols rows (> cols 0) (> rows 0))
+              (values cols rows))))
+        (values 80 24))))
 
 (defmethod backend-write ((b simple-backend) string)
   (let ((stream (backend-output-stream b)))