diff --git a/lisp/ob-R.el b/lisp/ob-R.el
index 2d22a4657..67b9a68b1 100644
--- a/lisp/ob-R.el
+++ b/lisp/ob-R.el
@@ -519,7 +519,7 @@ by `org-babel-comint-async-filter'."
 	   (ess-eval-buffer nil)))
        tmp-file))
     (output
-     (let ((uuid (md5 (number-to-string (random 100000000))))
+     (let ((uuid (org-id-uuid))
            (ess-local-process-name
             (process-name (get-buffer-process session)))
            (ess-eval-visibly-p nil))
diff --git a/lisp/ob-python.el b/lisp/ob-python.el
index e78d950bd..456f2d489 100644
--- a/lisp/ob-python.el
+++ b/lisp/ob-python.el
@@ -398,7 +398,7 @@ by `org-babel-comint-async-filter'."
   (let ((python-shell-buffer-name (org-babel-python-without-earmuffs session)))
     (pcase result-type
       (`output
-       (let ((uuid (md5 (number-to-string (random 100000000)))))
+       (let ((uuid (org-id-uuid)))
          (with-temp-buffer
            (insert (format org-babel-python-async-indicator "start" uuid))
            (insert "\n")