diff --git a/lisp/ein-cell.el b/lisp/ein-cell.el
index cab09e9..0c3c199 100644
--- a/lisp/ein-cell.el
+++ b/lisp/ein-cell.el
@@ -255,7 +255,7 @@ auto-execution mode flag in the connected buffer is `t'.")))
 (defun ein:get-slide-show (cell)
   (let ((slide-type (slot-value cell 'slidetype))
         (ss-table (make-hash-table)))
-    (setf (gethash 'slide-type ss-table) slide-type)
+    (setf (gethash 'slide_type ss-table) slide-type)
     ss-table))
 
 (defun ein:preprocess-nb4-cell (cell-data)