diff --git a/testing/org-test.el b/testing/org-test.el
index 9f7bab9ea..65d157bca 100644
--- a/testing/org-test.el
+++ b/testing/org-test.el
@@ -457,7 +457,9 @@ Load all test files first."
   (let ((org-id-track-globally t)
 	(org-test-selector
 	 (if org-test-selector org-test-selector "\\(org\\|ob\\)"))
-	org-confirm-babel-evaluate org-startup-folded vc-handled-backends)
+	org-confirm-babel-evaluate org-startup-folded vc-handled-backends
+        ;; Catch errors in diary sexps better.
+        (calendar-debug-sexp t))
     (org-test-touch-all-examples)
     (org-test-update-id-locations)
     (org-test-load)
@@ -471,7 +473,9 @@ Load all test files first."
   (org-test-touch-all-examples)
   (org-test-update-id-locations)
   (org-test-load)
-  (ert "\\(org\\|ob\\)")
+  (let (;; Catch errors in diary sexps better.
+        (calendar-debug-sexp t))
+    (ert "\\(org\\|ob\\)"))
   (org-test-kill-all-examples))
 
 (defmacro org-test-at-time (time &rest body)