diff --git a/lib/Controller/DbController.php b/lib/Controller/DbController.php
index 2885e24..0d9fe8c 100644
--- a/lib/Controller/DbController.php
+++ b/lib/Controller/DbController.php
@@ -174,7 +174,7 @@ class DbController extends Controller
                 $stmt = $this->db->prepare($query);
                 $stmt->execute();
 
-                if ($statementType === 'SELECT' || ($statementType === 'WITH' && SqlGuard::isReadOnly($query))) {
+                if ($statementType === 'SELECT' || ($statementType !== 'SET' && SqlGuard::isReadOnly($query))) {
                     // Read row by row and stop at MAX_ROWS, instead of
                     // fetchAll() + array_slice — otherwise a SELECT without
                     // LIMIT on a huge table would still pull everything into
diff --git a/lib/Service/SqlGuard.php b/lib/Service/SqlGuard.php
index 6863798..53a6368 100644
--- a/lib/Service/SqlGuard.php
+++ b/lib/Service/SqlGuard.php
@@ -46,7 +46,7 @@ class SqlGuard
     private const WRITES_INSIDE_READ = [
         '/\b(INSERT|UPDATE|DELETE|MERGE|INTO|ANALYZE)\b/i',
         '/^SET\s+(SESSION\s+|LOCAL\s+)?(ROLE|SESSION\s+AUTHORIZATION)\b/i',
-        '/\b(pg_terminate_backend|pg_cancel_backend|pg_reload_conf|set_config|setval|lo_create|lo_put|lo_unlink|pg_switch_wal|pg_create_restore_point|pg_advisory_lock)\s*\(/i',
+        '/\b(pg_terminate_backend|pg_cancel_backend|pg_reload_conf|set_config|setval|nextval|lo_create|lo_put|lo_unlink|pg_switch_wal|pg_create_restore_point|pg_advisory_lock)\s*\(/i',
     ];
 
     /**
diff --git a/tests/Unit/Service/SqlGuardTest.php b/tests/Unit/Service/SqlGuardTest.php
index 27ad54a..23caacc 100644
--- a/tests/Unit/Service/SqlGuardTest.php
+++ b/tests/Unit/Service/SqlGuardTest.php
@@ -110,6 +110,7 @@ class SqlGuardTest extends TestCase
             ['SELECT pg_terminate_backend(123)'],
             ["SELECT set_config('x', 'y', false)"],
             ["SELECT setval('seq', 1)"],
+            ["SELECT nextval('seq')"],
             ['MERGE INTO t USING s ON true WHEN MATCHED THEN DELETE'],
             ['VACUUM'],
             ["WITH a AS (SELECT '/*'), b AS (DELETE FROM t RETURNING 1) SELECT '*/'"],