diff --git a/src/backend/modern.lisp b/src/backend/modern.lisp
index a0b8bd1..4c15fcf 100644
--- a/src/backend/modern.lisp
+++ b/src/backend/modern.lisp
@@ -164,29 +164,34 @@ 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))
+  (multiple-value-bind (w h)
+      (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 env vars — set by every POSIX shell.
-      ;; Catches cases where ioctl on stdout's fd disagrees with
-      ;; the real terminal size (e.g. stdout redirected or a
-      ;; file descriptor mismatch).
-      (ignore-errors
-        (let ((cols (parse-integer (sb-ext:posix-getenv "COLUMNS")
-                                   :junk-allowed t))
-              (rows (parse-integer (sb-ext:posix-getenv "LINES")
-                                   :junk-allowed t)))
-          (when (and cols rows (> cols 0) (> rows 0))
-            (values cols rows))))
-      (values 80 24)))
+                             (sb-alien:deref winsize 0))) ;; rows
+                (sb-alien:free-alien winsize))))
+          (values 0 0))
+    ;; If ioctl returned a plausible size (not the 80x24 default),
+    ;; trust it — it will be correct at runtime after SIGWINCH.
+    (if (and (> w 80) (> h 24))
+        (values w h)
+        ;; ioctl returned 80x24 or less — suspicious.  Try $COLUMNS/
+        ;; $LINES from the shell, which reflect the true size at
+        ;; process start even when ioctl on stdout's fd disagrees.
+        (or (ignore-errors
+              (let ((cols (parse-integer (sb-ext:posix-getenv "COLUMNS")
+                                         :junk-allowed t))
+                    (rows (parse-integer (sb-ext:posix-getenv "LINES")
+                                         :junk-allowed t)))
+                (when (and cols rows (> cols 0) (> rows 0))
+                  (values cols rows))))
+            (values w h)))))
 
 (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 4722ce4..570ab9b 100644
--- a/src/backend/simple.lisp
+++ b/src/backend/simple.lisp
@@ -27,26 +27,30 @@
   (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))))
-      (ignore-errors
-        (let ((cols (parse-integer (sb-ext:posix-getenv "COLUMNS")
-                                   :junk-allowed t))
-              (rows (parse-integer (sb-ext:posix-getenv "LINES")
-                                   :junk-allowed t)))
-          (when (and cols rows (> cols 0) (> rows 0))
-            (values cols rows))))
-      (values 80 24)))
+  (multiple-value-bind (w h)
+      (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))))
+          (values 0 0))
+    (if (and (> w 80) (> h 24))
+        (values w h)
+        (or (ignore-errors
+              (let ((cols (parse-integer (sb-ext:posix-getenv "COLUMNS")
+                                         :junk-allowed t))
+                    (rows (parse-integer (sb-ext:posix-getenv "LINES")
+                                         :junk-allowed t)))
+                (when (and cols rows (> cols 0) (> rows 0))
+                  (values cols rows))))
+            (values w h)))))
 
 (defmethod backend-write ((b simple-backend) string)
   (let ((stream (backend-output-stream b)))