diff --git a/jupyter-base.el b/jupyter-base.el
index 43e855b..a478446 100644
--- a/jupyter-base.el
+++ b/jupyter-base.el
@@ -175,7 +175,7 @@ returned."
   (declare (indent 3) (debug (symbolp symbolp form body)))
   `(let ((,beg (point-marker))
          (,end (point-marker)))
-     (set-marker-insertion-type end t)
+     (set-marker-insertion-type ,end t)
      (unwind-protect
          (prog1 ,bodyform ,@afterforms)
        (set-marker ,beg nil)
diff --git a/jupyter-mime.el b/jupyter-mime.el
index 8a28605..280e98d 100644
--- a/jupyter-mime.el
+++ b/jupyter-mime.el
@@ -92,12 +92,14 @@ find the display in the REPL buffer. See
   "Handle control codes in any produced output generated by evaluating BODY.
 After BODY is evaluated, call `jupyter-handle-control-codes'
 on the region inserted by BODY."
-  `(jupyter-with-insertion-bounds
-       beg end (progn ,@body)
-     ;; Handle continuation from previous messages
-     (when (eq (char-before beg) ?\r)
-       (move-marker beg (1- beg)))
-     (jupyter-handle-control-codes beg end)))
+  (let ((beg (make-symbol "beg"))
+        (end (make-symbol "end")))
+    `(jupyter-with-insertion-bounds
+         ,beg ,end (progn ,@body)
+       ;; Handle continuation from previous messages
+       (when (eq (char-before ,beg) ?\r)
+         (move-marker ,beg (1- ,beg)))
+       (jupyter-handle-control-codes ,beg ,end))))
 
 ;;; Fontificiation routines