diff --git a/local/packages-to-build.R b/local/packages-to-build.R
index 4f8df44..9d19b0b 100644
--- a/local/packages-to-build.R
+++ b/local/packages-to-build.R
@@ -1,5 +1,5 @@
 options(error = function() {
-  message(geterrmessage())
+  cat("ERROR:", geterrmessage(), "\n", file = stdout())
   traceback(2)
   q(status = 1)
 })