diff --git a/init.el b/init.el
index 47a3727..d402245 100644
--- a/init.el
+++ b/init.el
@@ -2208,7 +2208,8 @@ Note that this erases the buffer before doing anything."
        ,@body))
   (defun my/-sly-fontify-current-input ()
     "Function called from `post-command-hook' to fontify the current input."
-    (when-let ((proc (get-buffer-process (current-buffer)))
+    (when-let ((deactivate-mark nil)
+               (proc (get-buffer-process (current-buffer)))
                (start (process-mark proc))
                (end (point-max))
                (input (buffer-substring-no-properties start end))