diff --git a/phpstan-baseline.php b/phpstan-baseline.php
index cfee07815e8a..caaad61d6e84 100644
--- a/phpstan-baseline.php
+++ b/phpstan-baseline.php
@@ -3001,11 +3001,6 @@
 	'count' => 11,
 	'path' => __DIR__ . '/system/Database/MySQLi/Connection.php',
 ];
-$ignoreErrors[] = [
-	'message' => '#^Method CodeIgniter\\\\Database\\\\MySQLi\\\\Connection\\:\\:_close\\(\\) should return mixed but return statement is missing\\.$#',
-	'count' => 1,
-	'path' => __DIR__ . '/system/Database/MySQLi/Connection.php',
-];
 $ignoreErrors[] = [
 	'message' => '#^Only booleans are allowed in &&, int given on the left side\\.$#',
 	'count' => 1,
@@ -3391,11 +3386,6 @@
 	'count' => 2,
 	'path' => __DIR__ . '/system/Database/Postgre/Connection.php',
 ];
-$ignoreErrors[] = [
-	'message' => '#^Method CodeIgniter\\\\Database\\\\Postgre\\\\Connection\\:\\:_close\\(\\) should return mixed but return statement is missing\\.$#',
-	'count' => 1,
-	'path' => __DIR__ . '/system/Database/Postgre/Connection.php',
-];
 $ignoreErrors[] = [
 	'message' => '#^Method CodeIgniter\\\\Database\\\\Postgre\\\\Connection\\:\\:buildDSN\\(\\) has no return type specified\\.$#',
 	'count' => 1,
@@ -3756,11 +3746,6 @@
 	'count' => 1,
 	'path' => __DIR__ . '/system/Database/SQLSRV/Connection.php',
 ];
-$ignoreErrors[] = [
-	'message' => '#^Method CodeIgniter\\\\Database\\\\SQLSRV\\\\Connection\\:\\:_close\\(\\) should return mixed but return statement is missing\\.$#',
-	'count' => 1,
-	'path' => __DIR__ . '/system/Database/SQLSRV/Connection.php',
-];
 $ignoreErrors[] = [
 	'message' => '#^PHPDoc type string of property CodeIgniter\\\\Database\\\\SQLSRV\\\\Connection\\:\\:\\$escapeChar is not the same as PHPDoc type array\\|string of overridden property CodeIgniter\\\\Database\\\\BaseConnection\\<resource,resource\\>\\:\\:\\$escapeChar\\.$#',
 	'count' => 1,
@@ -3951,11 +3936,6 @@
 	'count' => 1,
 	'path' => __DIR__ . '/system/Database/SQLite3/Connection.php',
 ];
-$ignoreErrors[] = [
-	'message' => '#^Method CodeIgniter\\\\Database\\\\SQLite3\\\\Connection\\:\\:_close\\(\\) should return mixed but return statement is missing\\.$#',
-	'count' => 1,
-	'path' => __DIR__ . '/system/Database/SQLite3/Connection.php',
-];
 $ignoreErrors[] = [
 	'message' => '#^Method CodeIgniter\\\\Database\\\\SQLite3\\\\Connection\\:\\:getFieldNames\\(\\) return type has no value type specified in iterable type array\\.$#',
 	'count' => 1,
@@ -8661,11 +8641,6 @@
 	'count' => 1,
 	'path' => __DIR__ . '/system/Test/Mock/MockConnection.php',
 ];
-$ignoreErrors[] = [
-	'message' => '#^Method CodeIgniter\\\\Test\\\\Mock\\\\MockConnection\\:\\:_close\\(\\) should return mixed but return statement is missing\\.$#',
-	'count' => 1,
-	'path' => __DIR__ . '/system/Test/Mock/MockConnection.php',
-];
 $ignoreErrors[] = [
 	'message' => '#^Method CodeIgniter\\\\Test\\\\Mock\\\\MockConnection\\:\\:_fieldData\\(\\) return type has no value type specified in iterable type array\\.$#',
 	'count' => 1,
diff --git a/system/Database/BaseConnection.php b/system/Database/BaseConnection.php
index b597c6d6cd10..77c9bd39ef3e 100644
--- a/system/Database/BaseConnection.php
+++ b/system/Database/BaseConnection.php
@@ -479,7 +479,7 @@ public function close()
     /**
      * Platform dependent way method for closing the connection.
      *
-     * @return mixed
+     * @return void
      */
     abstract protected function _close();
 
diff --git a/system/Database/MySQLi/Connection.php b/system/Database/MySQLi/Connection.php
index c2ef98adb0b3..b25f2e1af390 100644
--- a/system/Database/MySQLi/Connection.php
+++ b/system/Database/MySQLi/Connection.php
@@ -246,6 +246,8 @@ public function reconnect()
 
     /**
      * Close the database connection.
+     *
+     * @return void
      */
     protected function _close()
     {
diff --git a/system/Database/Postgre/Connection.php b/system/Database/Postgre/Connection.php
index bce4209c64d2..126aa98bb1c2 100644
--- a/system/Database/Postgre/Connection.php
+++ b/system/Database/Postgre/Connection.php
@@ -146,6 +146,8 @@ public function reconnect()
 
     /**
      * Close the database connection.
+     *
+     * @return void
      */
     protected function _close()
     {
diff --git a/system/Database/SQLSRV/Connection.php b/system/Database/SQLSRV/Connection.php
index 411470d8e34c..0626a63c998b 100755
--- a/system/Database/SQLSRV/Connection.php
+++ b/system/Database/SQLSRV/Connection.php
@@ -173,6 +173,8 @@ public function reconnect()
 
     /**
      * Close the database connection.
+     *
+     * @return void
      */
     protected function _close()
     {
diff --git a/system/Database/SQLite3/Connection.php b/system/Database/SQLite3/Connection.php
index d15c64213952..945434184f33 100644
--- a/system/Database/SQLite3/Connection.php
+++ b/system/Database/SQLite3/Connection.php
@@ -110,6 +110,8 @@ public function reconnect()
 
     /**
      * Close the database connection.
+     *
+     * @return void
      */
     protected function _close()
     {
diff --git a/system/Test/Mock/MockConnection.php b/system/Test/Mock/MockConnection.php
index 83826c347c98..020d6e3dd340 100644
--- a/system/Test/Mock/MockConnection.php
+++ b/system/Test/Mock/MockConnection.php
@@ -220,6 +220,8 @@ protected function _foreignKeyData(string $table): array
 
     /**
      * Close the connection.
+     *
+     * @return void
      */
     protected function _close()
     {