diff --git a/src/bin/pg_verifybackup/t/007_wal.pl b/src/bin/pg_verifybackup/t/007_wal.pl
index 6e9fafcd55..9a21e8dc15 100644
--- a/src/bin/pg_verifybackup/t/007_wal.pl
+++ b/src/bin/pg_verifybackup/t/007_wal.pl
@@ -5,7 +5,6 @@
 
 use strict;
 use warnings;
-use File::Path qw(rmtree);
 use PostgreSQL::Test::Cluster;
 use PostgreSQL::Test::Utils;
 use Test::More;
diff --git a/src/test/recovery/t/004_timeline_switch.pl b/src/test/recovery/t/004_timeline_switch.pl
index 3203d93701..f946ce9f1c 100644
--- a/src/test/recovery/t/004_timeline_switch.pl
+++ b/src/test/recovery/t/004_timeline_switch.pl
@@ -4,7 +4,6 @@
 # Test for timeline switch
 use strict;
 use warnings;
-use File::Path qw(rmtree);
 use PostgreSQL::Test::Cluster;
 use PostgreSQL::Test::Utils;
 use Test::More;
diff --git a/src/test/recovery/t/019_replslot_limit.pl b/src/test/recovery/t/019_replslot_limit.pl
index 84c9c4b0b3..ce8d36b4c6 100644
--- a/src/test/recovery/t/019_replslot_limit.pl
+++ b/src/test/recovery/t/019_replslot_limit.pl
@@ -9,8 +9,6 @@ use warnings;
 
 use PostgreSQL::Test::Utils;
 use PostgreSQL::Test::Cluster;
-
-use File::Path qw(rmtree);
 use Test::More;
 use Time::HiRes qw(usleep);
 
@@ -429,7 +427,7 @@ sub advance_wal
 {
 	my ($node, $n) = @_;
 
-	# Advance by $n segments (= (16 * $n) MB) on primary
+	# Advance by $n segments (= (wal_segment_size * $n) bytes) on primary.
 	for (my $i = 0; $i < $n; $i++)
 	{
 		$node->safe_psql('postgres',