diff --git a/RoboFile.php b/RoboFile.php
index 4653e4c8..02ae1c42 100644
--- a/RoboFile.php
+++ b/RoboFile.php
@@ -45,7 +45,7 @@ class RoboFile extends \Robo\Tasks {
      * See help for the "test" task for more details. 
     */
     public function testQuick(array $args): Result {
-        return $this->test(array_merge(["--exclude-group","slow"], $args));
+        return $this->test(array_merge(["--exclude-group", "slow,optional"], $args));
     }
 
     /** Produces a code coverage report 
diff --git a/lib/Database.php b/lib/Database.php
index 0072cd86..6489e303 100644
--- a/lib/Database.php
+++ b/lib/Database.php
@@ -415,7 +415,7 @@ class Database {
         return $f;
     }
 
-    protected function folderValidateMove(string $user, int $id = null, $parent = null, string $name = null) {
+    protected function folderValidateMove(string $user, $id = null, $parent = null, string $name = null) {
         $errData = ["action" => $this->caller(), "field" => "parent", 'id' => $parent];
         if (!$id) {
             // the root cannot be moved
@@ -467,7 +467,7 @@ class Database {
         return $parent;
     }
 
-    protected function folderValidateName($name, bool $checkDuplicates = false, int $parent = null): bool {
+    protected function folderValidateName($name, bool $checkDuplicates = false, $parent = null): bool {
         $info = ValueInfo::str($name);
         if ($info & (ValueInfo::NULL | ValueInfo::EMPTY)) {
             throw new Db\ExceptionInput("missing", ["action" => $this->caller(), "field" => "name"]);
@@ -572,7 +572,7 @@ class Database {
             // add a suitable WHERE condition
             $q->setWhere("folder in (select folder from folders)");
         }
-        return $this->db->prepare($q->getQuery(), $q->getTypes())->run($q->getValues())->getValue();
+        return (int) $this->db->prepare($q->getQuery(), $q->getTypes())->run($q->getValues())->getValue();
     }
 
     public function subscriptionRemove(string $user, $id): bool {
@@ -1102,7 +1102,7 @@ class Database {
             $q = $this->articleQuery($user, $context);
             $q->pushCTE("selected_articles");
             $q->setBody("SELECT count(*) from selected_articles");
-            return $this->db->prepare($q->getQuery(), $q->getTypes())->run($q->getValues())->getValue();
+            return (int) $this->db->prepare($q->getQuery(), $q->getTypes())->run($q->getValues())->getValue();
         }
     }
 
diff --git a/tests/cases/Db/SQLite3PDO/Database/TestDatabaseArticleSQLite3PDO.php b/tests/cases/Db/SQLite3PDO/Database/TestDatabaseArticleSQLite3PDO.php
new file mode 100644
index 00000000..a904781e
--- /dev/null
+++ b/tests/cases/Db/SQLite3PDO/Database/TestDatabaseArticleSQLite3PDO.php
@@ -0,0 +1,16 @@
+<?php
+/** @license MIT
+ * Copyright 2017 J. King, Dustin Wilson et al.
+ * See LICENSE and AUTHORS files for details */
+
+declare(strict_types=1);
+namespace JKingWeb\Arsse;
+
+/** 
+ * @covers \JKingWeb\Arsse\Database<extended> 
+ * @group optional */
+class TestDatabaseArticleSQLite3PDO extends Test\AbstractTest {
+    use Test\Database\Setup;
+    use Test\Database\DriverSQLite3PDO;
+    use Test\Database\SeriesArticle;
+}
diff --git a/tests/cases/Db/SQLite3PDO/Database/TestDatabaseCleanupSQLite3PDO.php b/tests/cases/Db/SQLite3PDO/Database/TestDatabaseCleanupSQLite3PDO.php
new file mode 100644
index 00000000..8eb5ef7c
--- /dev/null
+++ b/tests/cases/Db/SQLite3PDO/Database/TestDatabaseCleanupSQLite3PDO.php
@@ -0,0 +1,16 @@
+<?php
+/** @license MIT
+ * Copyright 2017 J. King, Dustin Wilson et al.
+ * See LICENSE and AUTHORS files for details */
+
+declare(strict_types=1);
+namespace JKingWeb\Arsse;
+
+/** 
+ * @covers \JKingWeb\Arsse\Database<extended> 
+ * @group optional */
+class TestDatabaseCleanupSQLite3PDO extends Test\AbstractTest {
+    use Test\Database\Setup;
+    use Test\Database\DriverSQLite3PDO;
+    use Test\Database\SeriesCleanup;
+}
diff --git a/tests/cases/Db/SQLite3PDO/Database/TestDatabaseFeedSQLite3PDO.php b/tests/cases/Db/SQLite3PDO/Database/TestDatabaseFeedSQLite3PDO.php
new file mode 100644
index 00000000..07ed2ab1
--- /dev/null
+++ b/tests/cases/Db/SQLite3PDO/Database/TestDatabaseFeedSQLite3PDO.php
@@ -0,0 +1,16 @@
+<?php
+/** @license MIT
+ * Copyright 2017 J. King, Dustin Wilson et al.
+ * See LICENSE and AUTHORS files for details */
+
+declare(strict_types=1);
+namespace JKingWeb\Arsse;
+
+/** 
+ * @covers \JKingWeb\Arsse\Database<extended> 
+ * @group optional */
+class TestDatabaseFeedSQLite3PDO extends Test\AbstractTest {
+    use Test\Database\Setup;
+    use Test\Database\DriverSQLite3PDO;
+    use Test\Database\SeriesFeed;
+}
diff --git a/tests/cases/Db/SQLite3PDO/Database/TestDatabaseFolderSQLite3PDO.php b/tests/cases/Db/SQLite3PDO/Database/TestDatabaseFolderSQLite3PDO.php
new file mode 100644
index 00000000..d348de95
--- /dev/null
+++ b/tests/cases/Db/SQLite3PDO/Database/TestDatabaseFolderSQLite3PDO.php
@@ -0,0 +1,16 @@
+<?php
+/** @license MIT
+ * Copyright 2017 J. King, Dustin Wilson et al.
+ * See LICENSE and AUTHORS files for details */
+
+declare(strict_types=1);
+namespace JKingWeb\Arsse;
+
+/** 
+ * @covers \JKingWeb\Arsse\Database<extended> 
+ * @group optional */
+class TestDatabaseFolderSQLite3PDO extends Test\AbstractTest {
+    use Test\Database\Setup;
+    use Test\Database\DriverSQLite3PDO;
+    use Test\Database\SeriesFolder;
+}
diff --git a/tests/cases/Db/SQLite3PDO/Database/TestDatabaseLabelSQLite3PDO.php b/tests/cases/Db/SQLite3PDO/Database/TestDatabaseLabelSQLite3PDO.php
new file mode 100644
index 00000000..3d367af3
--- /dev/null
+++ b/tests/cases/Db/SQLite3PDO/Database/TestDatabaseLabelSQLite3PDO.php
@@ -0,0 +1,12 @@
+<?php
+declare(strict_types=1);
+namespace JKingWeb\Arsse;
+
+/** 
+ * @covers \JKingWeb\Arsse\Database<extended> 
+ * @group optional */
+class TestDatabaseLabelSQLite3PDO extends Test\AbstractTest {
+    use Test\Database\Setup;
+    use Test\Database\DriverSQLite3PDO;
+    use Test\Database\SeriesLabel;
+}
diff --git a/tests/cases/Db/SQLite3PDO/Database/TestDatabaseMetaSQLite3PDO.php b/tests/cases/Db/SQLite3PDO/Database/TestDatabaseMetaSQLite3PDO.php
new file mode 100644
index 00000000..8f8ad5eb
--- /dev/null
+++ b/tests/cases/Db/SQLite3PDO/Database/TestDatabaseMetaSQLite3PDO.php
@@ -0,0 +1,16 @@
+<?php
+/** @license MIT
+ * Copyright 2017 J. King, Dustin Wilson et al.
+ * See LICENSE and AUTHORS files for details */
+
+declare(strict_types=1);
+namespace JKingWeb\Arsse;
+
+/** 
+ * @covers \JKingWeb\Arsse\Database<extended> 
+ * @group optional */
+class TestDatabaseMetaSQLite3PDO extends Test\AbstractTest {
+    use Test\Database\Setup;
+    use Test\Database\DriverSQLite3PDO;
+    use Test\Database\SeriesMeta;
+}
diff --git a/tests/cases/Db/SQLite3PDO/Database/TestDatabaseMiscellanySQLite3PDO.php b/tests/cases/Db/SQLite3PDO/Database/TestDatabaseMiscellanySQLite3PDO.php
new file mode 100644
index 00000000..2e1d01e6
--- /dev/null
+++ b/tests/cases/Db/SQLite3PDO/Database/TestDatabaseMiscellanySQLite3PDO.php
@@ -0,0 +1,16 @@
+<?php
+/** @license MIT
+ * Copyright 2017 J. King, Dustin Wilson et al.
+ * See LICENSE and AUTHORS files for details */
+
+declare(strict_types=1);
+namespace JKingWeb\Arsse;
+
+/** 
+ * @covers \JKingWeb\Arsse\Database<extended> 
+ * @group optional */
+class TestDatabaseMiscellanySQLite3PDO extends Test\AbstractTest {
+    use Test\Database\Setup;
+    use Test\Database\DriverSQLite3PDO;
+    use Test\Database\SeriesMiscellany;
+}
diff --git a/tests/cases/Db/SQLite3PDO/Database/TestDatabaseSessionSQLite3PDO.php b/tests/cases/Db/SQLite3PDO/Database/TestDatabaseSessionSQLite3PDO.php
new file mode 100644
index 00000000..bd0a857d
--- /dev/null
+++ b/tests/cases/Db/SQLite3PDO/Database/TestDatabaseSessionSQLite3PDO.php
@@ -0,0 +1,12 @@
+<?php
+declare(strict_types=1);
+namespace JKingWeb\Arsse;
+
+/** 
+ * @covers \JKingWeb\Arsse\Database<extended> 
+ * @group optional */
+class TestDatabaseSessionSQLite3PDO extends Test\AbstractTest {
+    use Test\Database\Setup;
+    use Test\Database\DriverSQLite3PDO;
+    use Test\Database\SeriesSession;
+}
diff --git a/tests/cases/Db/SQLite3PDO/Database/TestDatabaseSubscriptionSQLite3PDO.php b/tests/cases/Db/SQLite3PDO/Database/TestDatabaseSubscriptionSQLite3PDO.php
new file mode 100644
index 00000000..99ec86c5
--- /dev/null
+++ b/tests/cases/Db/SQLite3PDO/Database/TestDatabaseSubscriptionSQLite3PDO.php
@@ -0,0 +1,16 @@
+<?php
+/** @license MIT
+ * Copyright 2017 J. King, Dustin Wilson et al.
+ * See LICENSE and AUTHORS files for details */
+
+declare(strict_types=1);
+namespace JKingWeb\Arsse;
+
+/** 
+ * @covers \JKingWeb\Arsse\Database<extended> 
+ * @group optional */
+class TestDatabaseSubscriptionSQLite3PDO extends Test\AbstractTest {
+    use Test\Database\Setup;
+    use Test\Database\DriverSQLite3PDO;
+    use Test\Database\SeriesSubscription;
+}
diff --git a/tests/cases/Db/SQLite3PDO/Database/TestDatabaseUserSQLite3PDO.php b/tests/cases/Db/SQLite3PDO/Database/TestDatabaseUserSQLite3PDO.php
new file mode 100644
index 00000000..ef5ec44c
--- /dev/null
+++ b/tests/cases/Db/SQLite3PDO/Database/TestDatabaseUserSQLite3PDO.php
@@ -0,0 +1,16 @@
+<?php
+/** @license MIT
+ * Copyright 2017 J. King, Dustin Wilson et al.
+ * See LICENSE and AUTHORS files for details */
+
+declare(strict_types=1);
+namespace JKingWeb\Arsse;
+
+/** 
+ * @covers \JKingWeb\Arsse\Database<extended> 
+ * @group optional */
+class TestDatabaseUserSQLite3PDO extends Test\AbstractTest {
+    use Test\Database\Setup;
+    use Test\Database\DriverSQLite3PDO;
+    use Test\Database\SeriesUser;
+}
diff --git a/tests/lib/AbstractTest.php b/tests/lib/AbstractTest.php
index 85bb0eb9..dd63b4df 100644
--- a/tests/lib/AbstractTest.php
+++ b/tests/lib/AbstractTest.php
@@ -32,6 +32,8 @@ abstract class AbstractTest extends \PHPUnit\Framework\TestCase {
     public function approximateTime($exp, $act) {
         if (is_null($act)) {
             return null;
+        } elseif (is_null($exp)) {
+            return $act;
         }
         $target = Date::normalize($exp)->getTimeStamp();
         $value = Date::normalize($act)->getTimeStamp();
diff --git a/tests/lib/Database/DriverSQLite3PDO.php b/tests/lib/Database/DriverSQLite3PDO.php
new file mode 100644
index 00000000..9c52bd87
--- /dev/null
+++ b/tests/lib/Database/DriverSQLite3PDO.php
@@ -0,0 +1,24 @@
+<?php
+/** @license MIT
+ * Copyright 2017 J. King, Dustin Wilson et al.
+ * See LICENSE and AUTHORS files for details */
+
+declare(strict_types=1);
+namespace JKingWeb\Arsse\Test\Database;
+
+use JKingWeb\Arsse\Arsse;
+use JKingWeb\Arsse\Db\SQLite3\PDODriver;
+
+trait DriverSQLite3PDO {
+    public function setUpDriver() {
+        if (!PDODriver::requirementsMet()) {
+            $this->markTestSkipped("PDO-SQLite extension not loaded");
+        }
+        Arsse::$conf->dbSQLite3File = ":memory:";
+        $this->drv = new PDODriver();
+    }
+
+    public function nextID(string $table): int {
+        return (int) $this->drv->query("SELECT (case when max(id) then max(id) else 0 end)+1 from $table")->getValue();
+    }
+}
diff --git a/tests/lib/Database/SeriesArticle.php b/tests/lib/Database/SeriesArticle.php
index 82267115..7ffae2d1 100644
--- a/tests/lib/Database/SeriesArticle.php
+++ b/tests/lib/Database/SeriesArticle.php
@@ -888,8 +888,8 @@ trait SeriesArticle {
     public function testFetchStarredCounts() {
         $exp1 = ['total' => 2, 'unread' => 1, 'read' => 1];
         $exp2 = ['total' => 0, 'unread' => 0, 'read' => 0];
-        $this->assertSame($exp1, Arsse::$db->articleStarred("john.doe@example.com"));
-        $this->assertSame($exp2, Arsse::$db->articleStarred("jane.doe@example.com"));
+        $this->assertEquals($exp1, Arsse::$db->articleStarred("john.doe@example.com"));
+        $this->assertEquals($exp2, Arsse::$db->articleStarred("jane.doe@example.com"));
     }
 
     public function testFetchStarredCountsWithoutAuthority() {
diff --git a/tests/lib/Database/SeriesFeed.php b/tests/lib/Database/SeriesFeed.php
index e605bd49..fcfaf6b6 100644
--- a/tests/lib/Database/SeriesFeed.php
+++ b/tests/lib/Database/SeriesFeed.php
@@ -256,9 +256,9 @@ trait SeriesFeed {
     }
 
     public function testListStaleFeeds() {
-        $this->assertSame([1,3,4], Arsse::$db->feedListStale());
+        $this->assertEquals([1,3,4], Arsse::$db->feedListStale());
         Arsse::$db->feedUpdate(3);
         Arsse::$db->feedUpdate(4);
-        $this->assertSame([1], Arsse::$db->feedListStale());
+        $this->assertEquals([1], Arsse::$db->feedListStale());
     }
 }
diff --git a/tests/lib/Database/Setup.php b/tests/lib/Database/Setup.php
index 0adb9d3a..41428187 100644
--- a/tests/lib/Database/Setup.php
+++ b/tests/lib/Database/Setup.php
@@ -10,6 +10,7 @@ use JKingWeb\Arsse\User\Driver as UserDriver;
 use JKingWeb\Arsse\Arsse;
 use JKingWeb\Arsse\Conf;
 use JKingWeb\Arsse\User;
+use JKingWeb\Arsse\Misc\ValueInfo;
 use JKingWeb\Arsse\Test\Database;
 use JKingWeb\Arsse\Db\Result;
 use Phake;
@@ -90,8 +91,19 @@ trait Setup {
                 $row = array_combine($cols, $row);
                 foreach($data as $index => $test) {
                     foreach ($test as $col => $value) {
-                        if ($types[$col]=="datetime") {
-                            $test[$col] = $this->approximateTime($row[$col], $value);
+                        switch ($types[$col]) {
+                            case "datetime":
+                                $test[$col] = $this->approximateTime($row[$col], $value);
+                                break;
+                            case "int":
+                                $test[$col] = ValueInfo::normalize($value, ValueInfo::T_INT | ValueInfo::M_DROP | valueInfo::M_NULL);
+                                break;
+                            case "float":
+                                $test[$col] = ValueInfo::normalize($value, ValueInfo::T_FLOAT | ValueInfo::M_DROP | valueInfo::M_NULL);
+                                break;
+                            case "bool":
+                                $test[$col] = (int) ValueInfo::normalize($value, ValueInfo::T_BOOL | ValueInfo::M_DROP | valueInfo::M_NULL);
+                                break;                            
                         }
                     }
                     if($row===$test) {
diff --git a/tests/phpunit.xml b/tests/phpunit.xml
index c15db129..37e5bbef 100644
--- a/tests/phpunit.xml
+++ b/tests/phpunit.xml
@@ -58,7 +58,7 @@
         <file>cases/Db/SQLite3PDO/TestDbDriverSQLite3PDO.php</file>
         <file>cases/Db/SQLite3PDO/TestDbUpdateSQLite3PDO.php</file>
     </testsuite>
-    <testsuite name="Database functions">        
+    <testsuite name="Database functions">
         <file>cases/Db/SQLite3/Database/TestDatabaseMiscellanySQLite3.php</file>
         <file>cases/Db/SQLite3/Database/TestDatabaseMetaSQLite3.php</file>
         <file>cases/Db/SQLite3/Database/TestDatabaseUserSQLite3.php</file>
@@ -69,6 +69,16 @@
         <file>cases/Db/SQLite3/Database/TestDatabaseArticleSQLite3.php</file>
         <file>cases/Db/SQLite3/Database/TestDatabaseLabelSQLite3.php</file>
         <file>cases/Db/SQLite3/Database/TestDatabaseCleanupSQLite3.php</file>
+
+        <file>cases/Db/SQLite3PDO/Database/TestDatabaseMiscellanySQLite3PDO.php</file>
+        <file>cases/Db/SQLite3PDO/Database/TestDatabaseUserSQLite3PDO.php</file>
+        <file>cases/Db/SQLite3PDO/Database/TestDatabaseSessionSQLite3PDO.php</file>
+        <file>cases/Db/SQLite3PDO/Database/TestDatabaseFolderSQLite3PDO.php</file>
+        <file>cases/Db/SQLite3PDO/Database/TestDatabaseFeedSQLite3PDO.php</file>
+        <file>cases/Db/SQLite3PDO/Database/TestDatabaseSubscriptionSQLite3PDO.php</file>
+        <file>cases/Db/SQLite3PDO/Database/TestDatabaseArticleSQLite3PDO.php</file>
+        <file>cases/Db/SQLite3PDO/Database/TestDatabaseLabelSQLite3PDO.php</file>
+        <file>cases/Db/SQLite3PDO/Database/TestDatabaseCleanupSQLite3PDO.php</file>
     </testsuite>
     <testsuite name="Controllers">
         <testsuite name="NCNv1">