diff --git a/core/autoload/editor.el b/core/autoload/editor.el
index 0660813a9..209d15f71 100644
--- a/core/autoload/editor.el
+++ b/core/autoload/editor.el
@@ -112,7 +112,7 @@ possible, or just one char if that's not possible."
           (setq movement tab-width))
         (save-match-data
           (if (string-match "\\w*\\(\\s-+\\)$"
-                            (buffer-substring-no-properties (- p movement) p))
+                            (buffer-substring-no-properties (max (point-min) (- p movement)) p))
               (delete-char (- 0 (- (match-end 1) (match-beginning 1))))
             (call-interactively 'delete-backward-char)))))
      ;; Otherwise do a regular delete