diff --git a/tests/php/Dev/BacktraceTest.php b/tests/php/Dev/BacktraceTest.php
index 2435ab5c8b4..682c12018ec 100644
--- a/tests/php/Dev/BacktraceTest.php
+++ b/tests/php/Dev/BacktraceTest.php
@@ -161,7 +161,7 @@ public static function matchesFilterableClassProvider(): array
     #[DataProvider('matchesFilterableClassProvider')]
     public function testMatchesFilterableClass(string $className, string $filterableClass, bool $expected, string $message): void
     {
-        $reflectionMethod = new ReflectionMethod(Backtrace::class . '::matchesFilterableClass');
+        $reflectionMethod = new ReflectionMethod(Backtrace::class, 'matchesFilterableClass');
         $reflectionMethod->setAccessible(true);
         $this->assertSame($expected, $reflectionMethod->invoke(null, $className, $filterableClass), $message);
     }
diff --git a/tests/php/Dev/CsvBulkLoaderTest.php b/tests/php/Dev/CsvBulkLoaderTest.php
index 8f5d84834c4..8d1a5fb69db 100644
--- a/tests/php/Dev/CsvBulkLoaderTest.php
+++ b/tests/php/Dev/CsvBulkLoaderTest.php
@@ -57,8 +57,8 @@ public function testLoad()
         $filepath = $this->csvPath . 'PlayersWithHeader.csv';
         $file = fopen($filepath ?? '', 'r');
         $compareCount = $this->getLineCount($file);
-        fgetcsv($file); // pop header row
-        $compareRow = fgetcsv($file);
+        fgetcsv($file, escape: "\\"); // pop header row
+        $compareRow = fgetcsv($file, escape: "\\");
         $results = $loader->load($filepath);
 
         // Test that right amount of columns was imported
@@ -141,7 +141,7 @@ public function testLoadWithColumnMap()
         $filepath = $this->csvPath . 'Players.csv';
         $file = fopen($filepath ?? '', 'r');
         $compareCount = $this->getLineCount($file);
-        $compareRow = fgetcsv($file);
+        $compareRow = fgetcsv($file, escape: "\\");
         $loader->columnMap = [
             'FirstName',
             'Biography',
@@ -188,8 +188,8 @@ public function testLoadWithCustomHeaderAndRelation()
         $filepath = $this->csvPath . 'PlayersWithCustomHeaderAndRelation.csv';
         $file = fopen($filepath ?? '', 'r');
         $compareCount = $this->getLineCount($file);
-        fgetcsv($file); // pop header row
-        $compareRow = fgetcsv($file);
+        fgetcsv($file, escape: "\\"); // pop header row
+        $compareRow = fgetcsv($file, escape: "\\");
         $loader->columnMap = [
             'first name' => 'FirstName',
             'bio' => 'Biography',
diff --git a/tests/php/Dev/SapphireTestTest.php b/tests/php/Dev/SapphireTestTest.php
index cee251278ab..7074dd52dd9 100644
--- a/tests/php/Dev/SapphireTestTest.php
+++ b/tests/php/Dev/SapphireTestTest.php
@@ -9,7 +9,6 @@
 use SilverStripe\Security\Permission;
 use PHPUnit\Framework\Attributes\DataProvider;
 use PHPUnit\Framework\Attributes\DataProviderExternal;
-use SilverStripe\Dev\Exceptions\ExpectedErrorException;
 use SilverStripe\Dev\Exceptions\ExpectedNoticeException;
 use SilverStripe\Dev\Exceptions\ExpectedWarningException;
 
@@ -271,11 +270,8 @@ public function testEnableErrorHandler(int $errno, ?string $expectedClass): void
     public static function provideEnableErrorHandler(): array
     {
         // Only E_USER_* errors can be triggered, so that's all that's being tested
+        // As of PHP 8.4, E_USER_ERROR can no longer be triggered without a PHP deprecation notice
         return [
-            'error' => [
-                'errno' => E_USER_ERROR,
-                'expectedClass' => ExpectedErrorException::class,
-            ],
             'notice' => [
                 'errno' => E_USER_NOTICE,
                 'expectedClass' => ExpectedNoticeException::class,
diff --git a/tests/php/Forms/FormFieldTest.php b/tests/php/Forms/FormFieldTest.php
index 0611999e6e0..cab62ddccee 100644
--- a/tests/php/Forms/FormFieldTest.php
+++ b/tests/php/Forms/FormFieldTest.php
@@ -93,7 +93,6 @@
 use SilverStripe\Core\Validation\FieldValidation\OptionFieldValidator;
 use SilverStripe\ORM\DataList;
 use SilverStripe\Forms\DropdownField;
-use SilverStripe\Forms\SegmentField;
 use SilverStripe\Core\Validation\FieldValidation\TimeFieldValidator;
 use SilverStripe\Core\Validation\FieldValidation\DatetimeFieldValidator;
 
@@ -932,9 +931,6 @@ public function testFieldValidatorConfig(): void
             SelectionGroup_Item::class => [
                 CompositeFieldValidator::class,
             ],
-            SegmentField::class => [
-                StringFieldValidator::class,
-            ],
             SingleLookupField::class => [],
             Tab::class => [
                 CompositeFieldValidator::class,
@@ -969,6 +965,12 @@ public function testFieldValidatorConfig(): void
         ];
         $count = 0;
         foreach ($this->getFormFieldClasses() as $class) {
+            // skip any class with a core namespace that resides in an optional module that
+            // is included in silverstripe/recipe-kitchen-sink, and not in silverstripe/installer
+            if ($class === 'SilverStripe\\Forms\\SegmentField') {
+                // class if from silverstripe/segment-field
+                continue;
+            }
             if (!array_key_exists($class, $expectedFieldValidators)) {
                 throw new Exception("No field validator config found for $class");
             }
@@ -983,7 +985,7 @@ public function testFieldValidatorConfig(): void
         }
         // Assert that we have tested all classes e.g. namespace wasn't changed, no new classes were added
         // that haven't been tested
-        $this->assertSame(58, $count);
+        $this->assertSame(57, $count);
     }
 
     private function instantiateFormField(string $class): FormField