diff --git a/kagi.el b/kagi.el
index 886005f..4895ecb 100644
--- a/kagi.el
+++ b/kagi.el
@@ -436,9 +436,9 @@ result is short, otherwise it is displayed in a new buffer."
    (list (if (use-region-p)
              (buffer-substring-no-properties (region-beginning) (region-end))
            (let ((buffer-or-text (read-buffer (format-prompt "Buffer name or text" nil))))
-             (if (get-buffer buffer-or-text)
-                 (buffer-string)
-               buffer-or-text)))
+             (cond ((get-buffer buffer-or-text) (buffer-string))
+                   ((< 0 (length buffer-or-text)) buffer-or-text)
+                   (t (error "No buffer or text entered")))))
          (kagi--read-language (format-prompt "Target language" nil))
          (when (equal current-prefix-arg '(4))
            (kagi--read-language (format-prompt "Source language" nil)))