diff --git a/src/test/perl/PostgreSQL/Test/Cluster.pm b/src/test/perl/PostgreSQL/Test/Cluster.pm
index 2e31c23a6ac..7049aa3128b 100644
--- a/src/test/perl/PostgreSQL/Test/Cluster.pm
+++ b/src/test/perl/PostgreSQL/Test/Cluster.pm
@@ -2720,8 +2720,10 @@ sub poll_query_until
 
 	# Give up. Print the output from the last attempt, hopefully that's useful
 	# for debugging.
+	my $msg_query = $query;
+	$msg_query = '(connection attempt only)' unless defined $query;
 	diag qq(poll_query_until timed out executing this query:
-$query
+$msg_query
 expecting this output:
 $expected
 last actual query output: