diff --git a/src/backend/backup/walsummary.c b/src/backend/backup/walsummary.c
index ae314d8b74d..867870aaad7 100644
--- a/src/backend/backup/walsummary.c
+++ b/src/backend/backup/walsummary.c
@@ -258,7 +258,7 @@ RemoveWalSummaryIfOlderThan(WalSummaryFile *ws, time_t cutoff_time)
 #else
 	ereport(LOG,
 			(errmsg_internal("removing file \"%s\" cutoff_time=%llu", path,
-			 (unsigned long long) cutoff_time)));
+							 (unsigned long long) cutoff_time)));
 #endif
 }
 
diff --git a/src/bin/pg_walsummary/t/002_blocks.pl b/src/bin/pg_walsummary/t/002_blocks.pl
index 40908da8cb4..eb128f460c1 100644
--- a/src/bin/pg_walsummary/t/002_blocks.pl
+++ b/src/bin/pg_walsummary/t/002_blocks.pl
@@ -13,13 +13,6 @@ $node1->init(has_archiving => 1, allows_streaming => 1);
 $node1->append_conf('postgresql.conf', 'summarize_wal = on');
 $node1->start;
 
-# See what's been summarized up until now.
-my $progress = $node1->safe_psql('postgres', <<EOM);
-SELECT summarized_tli, summarized_lsn FROM pg_get_wal_summarizer_state()
-EOM
-my ($summarized_tli, $summarized_lsn) = split(/\|/, $progress);
-note("before insert, summarized TLI $summarized_tli through $summarized_lsn");
-
 # Create a table and insert a few test rows into it. VACUUM FREEZE it so that
 # autovacuum doesn't induce any future modifications unexpectedly. Then
 # trigger a checkpoint.
@@ -31,22 +24,33 @@ SELECT
 FROM
 	generate_series(1, 400) g;
 VACUUM FREEZE;
+EOM
+
+# Record the current WAL insert LSN.
+my $base_lsn = $node1->safe_psql('postgres', <<EOM);
+SELECT pg_current_wal_insert_lsn()
+EOM
+note("just after insert, WAL insert LSN is $base_lsn");
+
+# Now perform a CHECKPOINT.
+$node1->safe_psql('postgres', <<EOM);
 CHECKPOINT;
 EOM
 
-# Wait for a new summary to show up.
-$node1->poll_query_until('postgres', <<EOM);
+# Wait for a new summary to show up, one that includes the inserts we just did.
+my $result = $node1->poll_query_until('postgres', <<EOM);
 SELECT EXISTS (
     SELECT * from pg_available_wal_summaries()
-    WHERE tli = $summarized_tli AND end_lsn > '$summarized_lsn'
+    WHERE end_lsn >= '$base_lsn'
 )
 EOM
+ok($result, "WAL summarization caught up after insert");
 
-# Again check the progress of WAL summarization.
-$progress = $node1->safe_psql('postgres', <<EOM);
+# Get a list of what summaries we now have.
+my $progress = $node1->safe_psql('postgres', <<EOM);
 SELECT summarized_tli, summarized_lsn FROM pg_get_wal_summarizer_state()
 EOM
-($summarized_tli, $summarized_lsn) = split(/\|/, $progress);
+my ($summarized_tli, $summarized_lsn) = split(/\|/, $progress);
 note("after insert, summarized TLI $summarized_tli through $summarized_lsn");
 note_wal_summary_dir("after insert", $node1);
 
@@ -56,20 +60,23 @@ UPDATE mytable SET b = 'abcdefghijklmnopqrstuvwxyz' WHERE a = 2;
 CHECKPOINT;
 EOM
 
-# Again wait for a new summary to show up.
-$node1->poll_query_until('postgres', <<EOM);
+# Wait for a new summary to show up.
+$result = $node1->poll_query_until('postgres', <<EOM);
 SELECT EXISTS (
     SELECT * from pg_available_wal_summaries()
     WHERE tli = $summarized_tli AND end_lsn > '$summarized_lsn'
 )
 EOM
+ok($result, "got new WAL summary after update");
 
 # Figure out the exact details for the new summary file.
 my $details = $node1->safe_psql('postgres', <<EOM);
 SELECT tli, start_lsn, end_lsn from pg_available_wal_summaries()
 	WHERE tli = $summarized_tli AND end_lsn > '$summarized_lsn'
 EOM
-my ($tli, $start_lsn, $end_lsn) = split(/\|/, $details);
+my @lines = split(/\n/, $details);
+is(0+@lines, 1, "got exactly one new WAL summary");
+my ($tli, $start_lsn, $end_lsn) = split(/\|/, $lines[0]);
 note("examining summary for TLI $tli from $start_lsn to $end_lsn");
 note_wal_summary_dir("after new summary", $node1);
 
@@ -81,12 +88,14 @@ my $filename = sprintf "%s/pg_wal/summaries/%08s%08s%08s%08s%08s.summary",
 ok(-f $filename, "WAL summary file exists");
 note_wal_summary_dir("after existence check", $node1);
 
-# Run pg_walsummary on it. We expect block 0 to be modified, but depending
-# on where the new tuple ends up, block 1 might also be modified, so we
-# pass -i to pg_walsummary to make sure we don't end up with a 0..1 range.
+# Run pg_walsummary on it. We expect exactly two blocks to be modified,
+# block 0 and one other.
 my ($stdout, $stderr) = run_command([ 'pg_walsummary', '-i', $filename ]);
+note($stdout);
+@lines = split(/\n/, $stdout);
 like($stdout, qr/FORK main: block 0$/m, "stdout shows block 0 modified");
 is($stderr, '', 'stderr is empty');
+is(0+@lines, 2, "UPDATE modified 2 blocks");
 note_wal_summary_dir("after pg_walsummary run", $node1);
 
 done_testing();