diff --git a/codex.el b/codex.el
index 572db00..09aa264 100644
--- a/codex.el
+++ b/codex.el
@@ -180,9 +180,20 @@
 
 (defun codex--get-current-user-prompt ()
   (with-codex-buffer
-    (unless codex--prompt-start
-      (error "No current prompt start"))
-    (buffer-substring-no-properties codex--prompt-start (point-max))))
+    (let ((prompt-start (and codex--prompt-start
+                             (marker-buffer codex--prompt-start)
+                             (marker-position codex--prompt-start))))
+      ;; fallback in case we somehow lost where our user prompt starts
+      (unless prompt-start
+        (let* ((haystack (buffer-string))
+               (needle "---\nUser:\n")
+               (index (cl-search needle haystack :from-end t)))
+          (when index
+            (setq prompt-start (+ (length needle) index))
+            (setq codex--prompt-start (copy-marker prompt-start)))))
+      (unless prompt-start
+        (error "No current prompt start"))
+      (buffer-substring-no-properties prompt-start (point-max)))))
 
 (defun codex-send ()
   (interactive)