diff --git a/src/test/perl/PostgresNode.pm b/src/test/perl/PostgresNode.pm
index e60673ad72..044b07790c 100644
--- a/src/test/perl/PostgresNode.pm
+++ b/src/test/perl/PostgresNode.pm
@@ -1348,9 +1348,18 @@ sub poll_query_until
 		$attempts++;
 	}
 
-	# The query result didn't change in 180 seconds. Give up. Print the stderr
-	# from the last attempt, hopefully that's useful for debugging.
-	diag $stderr;
+	# The query result didn't change in 180 seconds. Give up. Print the
+	# output from the last attempt, hopefully that's useful for debugging.
+	chomp($stderr);
+	$stderr =~ s/\r//g if $TestLib::windows_os;
+	diag qq(poll_query_until timed out executing this query:
+$query
+expecting this output:
+$expected
+last actual query output:
+$stdout
+with stderr:
+$stderr);
 	return 0;
 }