diff --git a/system/DataConverter/DataConverter.php b/system/DataConverter/DataConverter.php
index 4895ec4127d2..a1b5db4f0ef9 100644
--- a/system/DataConverter/DataConverter.php
+++ b/system/DataConverter/DataConverter.php
@@ -71,6 +71,8 @@ public function __construct(
      *
      * @param array<string, mixed> $data DataSource data
      *
+     * @return array<string, mixed>
+     *
      * @internal
      */
     public function fromDataSource(array $data): array
@@ -89,6 +91,8 @@ public function fromDataSource(array $data): array
      *
      * @param array<string, mixed> $phpData PHP data
      *
+     * @return array<string, mixed>
+     *
      * @internal
      */
     public function toDataSource(array $phpData): array
diff --git a/tests/system/DataConverter/DataConverterTest.php b/tests/system/DataConverter/DataConverterTest.php
index 6686618a181b..4ee4a8078217 100644
--- a/tests/system/DataConverter/DataConverterTest.php
+++ b/tests/system/DataConverter/DataConverterTest.php
@@ -44,6 +44,11 @@ public function testInstantiate(): void
         $this->assertInstanceOf(DataConverter::class, $converter);
     }
 
+    /**
+     * @param array<string, string> $types
+     * @param array<string, mixed>  $dbData
+     * @param array<string, mixed>  $expected
+     */
     #[DataProvider('provideConvertDataFromDB')]
     public function testConvertDataFromDB(array $types, array $dbData, array $expected): void
     {
@@ -54,6 +59,9 @@ public function testConvertDataFromDB(array $types, array $dbData, array $expect
         $this->assertSame($expected, $data);
     }
 
+    /**
+     * @return iterable<string, array{array<string, string>, array<string, mixed>, array<string, mixed>}>
+     */
     public static function provideConvertDataFromDB(): iterable
     {
         yield from [
@@ -270,6 +278,11 @@ public static function provideConvertDataFromDB(): iterable
         ];
     }
 
+    /**
+     * @param array<string, string> $types
+     * @param array<string, mixed>  $phpData
+     * @param array<string, mixed>  $expected
+     */
     #[DataProvider('provideConvertDataToDB')]
     public function testConvertDataToDB(array $types, array $phpData, array $expected): void
     {
@@ -280,6 +293,9 @@ public function testConvertDataToDB(array $types, array $phpData, array $expecte
         $this->assertSame($expected, $data);
     }
 
+    /**
+     * @return iterable<string, array{array<string, string>, array<string, mixed>, array<string, mixed>}>
+     */
     public static function provideConvertDataToDB(): iterable
     {
         yield from [
@@ -706,6 +722,8 @@ public function testNotNullable(): void
     }
 
     /**
+     * @param array<string, string>                                           $types
+     * @param array<string, class-string>                                     $handlers
      * @param (Closure(array<string, mixed>): object)|string|null             $reconstructor
      * @param (Closure(object, bool, bool): array<string, mixed>)|string|null $extractor
      */
diff --git a/utils/phpstan-baseline/loader.neon b/utils/phpstan-baseline/loader.neon
index d9cf5a7deb6d..8cfa166d48df 100644
--- a/utils/phpstan-baseline/loader.neon
+++ b/utils/phpstan-baseline/loader.neon
@@ -1,4 +1,4 @@
-# total 124 errors
+# total 112 errors
 
 includes:
     - argument.type.neon
diff --git a/utils/phpstan-baseline/missingType.iterableValue.neon b/utils/phpstan-baseline/missingType.iterableValue.neon
index ff0cd8e18d33..b426389b6a68 100644
--- a/utils/phpstan-baseline/missingType.iterableValue.neon
+++ b/utils/phpstan-baseline/missingType.iterableValue.neon
@@ -1,4 +1,4 @@
-# total 80 errors
+# total 68 errors
 
 parameters:
     ignoreErrors:
@@ -72,16 +72,6 @@ parameters:
             count: 1
             path: ../../system/Cookie/CookieStore.php
 
-        -
-            message: '#^Method CodeIgniter\\DataConverter\\DataConverter\:\:fromDataSource\(\) return type has no value type specified in iterable type array\.$#'
-            count: 1
-            path: ../../system/DataConverter/DataConverter.php
-
-        -
-            message: '#^Method CodeIgniter\\DataConverter\\DataConverter\:\:toDataSource\(\) return type has no value type specified in iterable type array\.$#'
-            count: 1
-            path: ../../system/DataConverter/DataConverter.php
-
         -
             message: '#^Method CodeIgniter\\Exceptions\\PageNotFoundException\:\:lang\(\) has parameter \$args with no value type specified in iterable type array\.$#'
             count: 1
@@ -307,56 +297,6 @@ parameters:
             count: 1
             path: ../../tests/system/Cookie/CookieTest.php
 
-        -
-            message: '#^Method CodeIgniter\\DataConverter\\DataConverterTest\:\:createDataConverter\(\) has parameter \$handlers with no value type specified in iterable type array\.$#'
-            count: 1
-            path: ../../tests/system/DataConverter/DataConverterTest.php
-
-        -
-            message: '#^Method CodeIgniter\\DataConverter\\DataConverterTest\:\:createDataConverter\(\) has parameter \$types with no value type specified in iterable type array\.$#'
-            count: 1
-            path: ../../tests/system/DataConverter/DataConverterTest.php
-
-        -
-            message: '#^Method CodeIgniter\\DataConverter\\DataConverterTest\:\:provideConvertDataFromDB\(\) return type has no value type specified in iterable type iterable\.$#'
-            count: 1
-            path: ../../tests/system/DataConverter/DataConverterTest.php
-
-        -
-            message: '#^Method CodeIgniter\\DataConverter\\DataConverterTest\:\:provideConvertDataToDB\(\) return type has no value type specified in iterable type iterable\.$#'
-            count: 1
-            path: ../../tests/system/DataConverter/DataConverterTest.php
-
-        -
-            message: '#^Method CodeIgniter\\DataConverter\\DataConverterTest\:\:testConvertDataFromDB\(\) has parameter \$dbData with no value type specified in iterable type array\.$#'
-            count: 1
-            path: ../../tests/system/DataConverter/DataConverterTest.php
-
-        -
-            message: '#^Method CodeIgniter\\DataConverter\\DataConverterTest\:\:testConvertDataFromDB\(\) has parameter \$expected with no value type specified in iterable type array\.$#'
-            count: 1
-            path: ../../tests/system/DataConverter/DataConverterTest.php
-
-        -
-            message: '#^Method CodeIgniter\\DataConverter\\DataConverterTest\:\:testConvertDataFromDB\(\) has parameter \$types with no value type specified in iterable type array\.$#'
-            count: 1
-            path: ../../tests/system/DataConverter/DataConverterTest.php
-
-        -
-            message: '#^Method CodeIgniter\\DataConverter\\DataConverterTest\:\:testConvertDataToDB\(\) has parameter \$expected with no value type specified in iterable type array\.$#'
-            count: 1
-            path: ../../tests/system/DataConverter/DataConverterTest.php
-
-        -
-            message: '#^Method CodeIgniter\\DataConverter\\DataConverterTest\:\:testConvertDataToDB\(\) has parameter \$phpData with no value type specified in iterable type array\.$#'
-            count: 1
-            path: ../../tests/system/DataConverter/DataConverterTest.php
-
-        -
-            message: '#^Method CodeIgniter\\DataConverter\\DataConverterTest\:\:testConvertDataToDB\(\) has parameter \$types with no value type specified in iterable type array\.$#'
-            count: 1
-            path: ../../tests/system/DataConverter/DataConverterTest.php
-
         -
             message: '#^Method CodeIgniter\\Models\\FindModelTest\:\:provideAggregateAndGroupBy\(\) return type has no value type specified in iterable type iterable\.$#'
             count: 1