diff --git a/libraries/classes/Controllers/Setup/ShowConfigController.php b/libraries/classes/Controllers/Setup/ShowConfigController.php
index 292da09d28..5c43dd067f 100644
--- a/libraries/classes/Controllers/Setup/ShowConfigController.php
+++ b/libraries/classes/Controllers/Setup/ShowConfigController.php
@@ -36,8 +36,6 @@ final class ShowConfigController
             $GLOBALS['ConfigFile']->resetConfigData();
             // drop post data
             $response->generateHeader303('../setup/index.php' . Url::getCommonRaw(['route' => '/setup']));
-
-            return;
         }
 
         /** @var mixed $submitDownload */
diff --git a/libraries/classes/Plugins/Auth/AuthenticationConfig.php b/libraries/classes/Plugins/Auth/AuthenticationConfig.php
index 3855062a0f..480d3a2c1f 100644
--- a/libraries/classes/Plugins/Auth/AuthenticationConfig.php
+++ b/libraries/classes/Plugins/Auth/AuthenticationConfig.php
@@ -28,20 +28,18 @@ class AuthenticationConfig extends AuthenticationPlugin
 {
     /**
      * Displays authentication form
-     *
-     * @return bool always true
      */
-    public function showLoginForm(): bool
+    public function showLoginForm(): void
     {
         $response = ResponseRenderer::getInstance();
-        if ($response->isAjax()) {
-            $response->setRequestStatus(false);
-            // reload_flag removes the token parameter from the URL and reloads
-            $response->addJSON('reload_flag', '1');
-            $response->callExit();
+        if (! $response->isAjax()) {
+            return;
         }
 
-        return true;
+        $response->setRequestStatus(false);
+        // reload_flag removes the token parameter from the URL and reloads
+        $response->addJSON('reload_flag', '1');
+        $response->callExit();
     }
 
     /**
@@ -66,7 +64,7 @@ class AuthenticationConfig extends AuthenticationPlugin
      *
      * @param string $failure String describing why authentication has failed
      */
-    public function showFailure(string $failure): void
+    public function showFailure(string $failure): never
     {
         parent::showFailure($failure);
 
diff --git a/libraries/classes/Plugins/Auth/AuthenticationCookie.php b/libraries/classes/Plugins/Auth/AuthenticationCookie.php
index 23366e32a5..f8f78bdd7f 100644
--- a/libraries/classes/Plugins/Auth/AuthenticationCookie.php
+++ b/libraries/classes/Plugins/Auth/AuthenticationCookie.php
@@ -63,7 +63,7 @@ class AuthenticationCookie extends AuthenticationPlugin
      *
      * @global string $conn_error the last connection error
      */
-    public function showLoginForm(): bool
+    public function showLoginForm(): never
     {
         $GLOBALS['conn_error'] ??= null;
 
@@ -379,7 +379,6 @@ class AuthenticationCookie extends AuthenticationPlugin
             SessionCache::remove('proc_priv');
 
             $this->showFailure('no-activity');
-            ResponseRenderer::getInstance()->callExit();
         }
 
         // check password cookie
@@ -552,12 +551,9 @@ class AuthenticationCookie extends AuthenticationPlugin
      * prepares error message and switches to showLoginForm() which display the error
      * and the login form
      *
-     * this function MUST exit/quit the application,
-     * currently done by call to showLoginForm()
-     *
      * @param string $failure String describing why authentication has failed
      */
-    public function showFailure(string $failure): void
+    public function showFailure(string $failure): never
     {
         $GLOBALS['conn_error'] ??= null;
 
diff --git a/libraries/classes/Plugins/Auth/AuthenticationHttp.php b/libraries/classes/Plugins/Auth/AuthenticationHttp.php
index ca8358200c..bb2b77c88e 100644
--- a/libraries/classes/Plugins/Auth/AuthenticationHttp.php
+++ b/libraries/classes/Plugins/Auth/AuthenticationHttp.php
@@ -30,10 +30,8 @@ class AuthenticationHttp extends AuthenticationPlugin
 {
     /**
      * Displays authentication form and redirect as necessary
-     *
-     * @return bool always true (no return indeed)
      */
-    public function showLoginForm(): bool
+    public function showLoginForm(): never
     {
         $response = ResponseRenderer::getInstance();
         if ($response->isAjax()) {
@@ -43,13 +41,13 @@ class AuthenticationHttp extends AuthenticationPlugin
             $response->callExit();
         }
 
-        return $this->authForm();
+        $this->authForm();
     }
 
     /**
      * Displays authentication form
      */
-    public function authForm(): bool
+    public function authForm(): never
     {
         if (empty($GLOBALS['cfg']['Server']['auth_http_realm'])) {
             if (empty($GLOBALS['cfg']['Server']['verbose'])) {
@@ -179,7 +177,7 @@ class AuthenticationHttp extends AuthenticationPlugin
      *
      * @param string $failure String describing why authentication has failed
      */
-    public function showFailure(string $failure): void
+    public function showFailure(string $failure): never
     {
         parent::showFailure($failure);
 
diff --git a/libraries/classes/Plugins/Auth/AuthenticationSignon.php b/libraries/classes/Plugins/Auth/AuthenticationSignon.php
index 418bb7f7a5..76f52dcc27 100644
--- a/libraries/classes/Plugins/Auth/AuthenticationSignon.php
+++ b/libraries/classes/Plugins/Auth/AuthenticationSignon.php
@@ -32,7 +32,7 @@ class AuthenticationSignon extends AuthenticationPlugin
     /**
      * Displays authentication form
      */
-    public function showLoginForm(): bool
+    public function showLoginForm(): never
     {
         $response = ResponseRenderer::getInstance();
         $response->disable();
@@ -244,7 +244,7 @@ class AuthenticationSignon extends AuthenticationPlugin
      *
      * @param string $failure String describing why authentication has failed
      */
-    public function showFailure(string $failure): void
+    public function showFailure(string $failure): never
     {
         parent::showFailure($failure);
 
diff --git a/libraries/classes/Plugins/AuthenticationPlugin.php b/libraries/classes/Plugins/AuthenticationPlugin.php
index a13f05611e..2a6071bef6 100644
--- a/libraries/classes/Plugins/AuthenticationPlugin.php
+++ b/libraries/classes/Plugins/AuthenticationPlugin.php
@@ -61,7 +61,7 @@ abstract class AuthenticationPlugin
     /**
      * Displays authentication form
      */
-    abstract public function showLoginForm(): bool;
+    abstract public function showLoginForm(): void;
 
     /**
      * Gets authentication credentials
diff --git a/libraries/classes/ResponseRenderer.php b/libraries/classes/ResponseRenderer.php
index cf05ce51d0..537fc7105a 100644
--- a/libraries/classes/ResponseRenderer.php
+++ b/libraries/classes/ResponseRenderer.php
@@ -439,7 +439,7 @@ class ResponseRenderer
      *
      * @param string $location will set location to redirect.
      */
-    public function generateHeader303(string $location): void
+    public function generateHeader303(string $location): never
     {
         $this->setHttpResponseCode(303);
         $this->header('Location: ' . $location);
diff --git a/libraries/classes/Setup/FormProcessing.php b/libraries/classes/Setup/FormProcessing.php
index 0efa6d786c..d3ee17c081 100644
--- a/libraries/classes/Setup/FormProcessing.php
+++ b/libraries/classes/Setup/FormProcessing.php
@@ -48,8 +48,6 @@ class FormProcessing
             $response = ResponseRenderer::getInstance();
             $response->disable();
             $response->generateHeader303('../setup/index.php' . Url::getCommonRaw(['route' => '/setup']));
-
-            return;
         }
 
         // form has errors, show warning
diff --git a/psalm-baseline.xml b/psalm-baseline.xml
index dc9dc053ee..9754ea64db 100644
--- a/psalm-baseline.xml
+++ b/psalm-baseline.xml
@@ -8177,9 +8177,6 @@
     <InvalidArrayOffset>
       <code><![CDATA[$GLOBALS['allowDeny_forbidden']]]></code>
     </InvalidArrayOffset>
-    <PossiblyUnusedReturnValue>
-      <code>bool</code>
-    </PossiblyUnusedReturnValue>
   </file>
   <file src="libraries/classes/Plugins/Auth/AuthenticationCookie.php">
     <DocblockTypeContradiction>
@@ -8243,7 +8240,6 @@
     </PossiblyNullReference>
     <PossiblyUnusedReturnValue>
       <code>bool</code>
-      <code>bool</code>
     </PossiblyUnusedReturnValue>
     <RedundantCast>
       <code><![CDATA[(int) $GLOBALS['cfg']['LoginCookieStore']]]></code>
@@ -8271,9 +8267,6 @@
     <PossiblyInvalidCast>
       <code>$oldUser</code>
     </PossiblyInvalidCast>
-    <PossiblyUnusedReturnValue>
-      <code>bool</code>
-    </PossiblyUnusedReturnValue>
   </file>
   <file src="libraries/classes/Plugins/Auth/AuthenticationSignon.php">
     <MixedArgument>
@@ -8297,9 +8290,6 @@
       <code><![CDATA[$this->password]]></code>
       <code><![CDATA[$this->user]]></code>
     </MixedAssignment>
-    <PossiblyUnusedReturnValue>
-      <code>bool</code>
-    </PossiblyUnusedReturnValue>
     <RedundantCast>
       <code><![CDATA[(array) $GLOBALS['cfg']['Server']['SignonCookieParams']]]></code>
     </RedundantCast>
@@ -8326,9 +8316,6 @@
     <PossiblyNullReference>
       <code>issetCookie</code>
     </PossiblyNullReference>
-    <PossiblyUnusedReturnValue>
-      <code>bool</code>
-    </PossiblyUnusedReturnValue>
   </file>
   <file src="libraries/classes/Plugins/AuthenticationPluginFactory.php">
     <RedundantFunctionCall>
diff --git a/test/classes/Plugins/Auth/AuthenticationConfigTest.php b/test/classes/Plugins/Auth/AuthenticationConfigTest.php
index dab16f20a3..ae0abac14d 100644
--- a/test/classes/Plugins/Auth/AuthenticationConfigTest.php
+++ b/test/classes/Plugins/Auth/AuthenticationConfigTest.php
@@ -94,7 +94,7 @@ class AuthenticationConfigTest extends AbstractTestCase
 
         $html = ob_get_clean();
 
-        $this->assertInstanceOf(ExitException::class, $throwable ?? null);
+        $this->assertInstanceOf(ExitException::class, $throwable);
 
         $this->assertIsString($html);
 
diff --git a/test/classes/Plugins/Auth/AuthenticationCookieTest.php b/test/classes/Plugins/Auth/AuthenticationCookieTest.php
index 885859e04b..48b5047902 100644
--- a/test/classes/Plugins/Auth/AuthenticationCookieTest.php
+++ b/test/classes/Plugins/Auth/AuthenticationCookieTest.php
@@ -73,7 +73,7 @@ class AuthenticationCookieTest extends AbstractNetworkTestCase
     }
 
     #[Group('medium')]
-    public function testAuthErrorAJAX(): void
+    public function testAuthErrorAJAX(): never
     {
         $mockResponse = $this->mockResponse();
 
@@ -191,7 +191,7 @@ class AuthenticationCookieTest extends AbstractNetworkTestCase
 
         $result = ob_get_clean();
 
-        $this->assertInstanceOf(ExitException::class, $throwable ?? null);
+        $this->assertInstanceOf(ExitException::class, $throwable);
 
         $this->assertIsString($result);
 
@@ -276,7 +276,7 @@ class AuthenticationCookieTest extends AbstractNetworkTestCase
 
         $result = ob_get_clean();
 
-        $this->assertInstanceOf(ExitException::class, $throwable ?? null);
+        $this->assertInstanceOf(ExitException::class, $throwable);
 
         $this->assertIsString($result);
 
@@ -355,7 +355,7 @@ class AuthenticationCookieTest extends AbstractNetworkTestCase
 
         $result = ob_get_clean();
 
-        $this->assertInstanceOf(ExitException::class, $throwable ?? null);
+        $this->assertInstanceOf(ExitException::class, $throwable);
 
         $this->assertIsString($result);
 
@@ -643,7 +643,8 @@ class AuthenticationCookieTest extends AbstractNetworkTestCase
             ->will($this->returnValue('testBF'));
 
         $this->object->expects($this->once())
-            ->method('showFailure');
+            ->method('showFailure')
+            ->willThrowException(new ExitException());
 
         $this->expectException(ExitException::class);
         $this->object->readCredentials();
@@ -711,6 +712,10 @@ class AuthenticationCookieTest extends AbstractNetworkTestCase
             ->onlyMethods(['showLoginForm'])
             ->getMock();
 
+        $this->object->expects($this->exactly(1))
+            ->method('showLoginForm')
+            ->willThrowException(new ExitException());
+
         $GLOBALS['server'] = 2;
         $_COOKIE['pmaAuth-2'] = 'pass';
 
@@ -718,7 +723,10 @@ class AuthenticationCookieTest extends AbstractNetworkTestCase
             ['Cache-Control: no-store, no-cache, must-revalidate'],
             ['Pragma: no-cache'],
         );
-        $this->object->showFailure('empty-denied');
+        try {
+            $this->object->showFailure('empty-denied');
+        } catch (ExitException) {
+        }
 
         $this->assertEquals(
             $GLOBALS['conn_error'],
@@ -773,6 +781,10 @@ class AuthenticationCookieTest extends AbstractNetworkTestCase
             ->onlyMethods(['showLoginForm'])
             ->getMock();
 
+        $this->object->expects($this->exactly(1))
+            ->method('showLoginForm')
+            ->willThrowException(new ExitException());
+
         $GLOBALS['server'] = 2;
         $_COOKIE['pmaAuth-2'] = 'pass';
 
@@ -780,7 +792,10 @@ class AuthenticationCookieTest extends AbstractNetworkTestCase
             ['Cache-Control: no-store, no-cache, must-revalidate'],
             ['Pragma: no-cache'],
         );
-        $this->object->showFailure('allow-denied');
+        try {
+            $this->object->showFailure('allow-denied');
+        } catch (ExitException) {
+        }
 
         $this->assertEquals($GLOBALS['conn_error'], 'Access denied!');
     }
@@ -792,6 +807,10 @@ class AuthenticationCookieTest extends AbstractNetworkTestCase
             ->onlyMethods(['showLoginForm'])
             ->getMock();
 
+        $this->object->expects($this->exactly(1))
+            ->method('showLoginForm')
+            ->willThrowException(new ExitException());
+
         $GLOBALS['server'] = 2;
         $_COOKIE['pmaAuth-2'] = 'pass';
 
@@ -802,7 +821,10 @@ class AuthenticationCookieTest extends AbstractNetworkTestCase
             ['Cache-Control: no-store, no-cache, must-revalidate'],
             ['Pragma: no-cache'],
         );
-        $this->object->showFailure('no-activity');
+        try {
+            $this->object->showFailure('no-activity');
+        } catch (ExitException) {
+        }
 
         $this->assertEquals(
             $GLOBALS['conn_error'],
@@ -818,6 +840,10 @@ class AuthenticationCookieTest extends AbstractNetworkTestCase
             ->onlyMethods(['showLoginForm'])
             ->getMock();
 
+        $this->object->expects($this->exactly(1))
+            ->method('showLoginForm')
+            ->willThrowException(new ExitException());
+
         $GLOBALS['server'] = 2;
         $_COOKIE['pmaAuth-2'] = 'pass';
 
@@ -836,7 +862,10 @@ class AuthenticationCookieTest extends AbstractNetworkTestCase
             ['Cache-Control: no-store, no-cache, must-revalidate'],
             ['Pragma: no-cache'],
         );
-        $this->object->showFailure('');
+        try {
+            $this->object->showFailure('');
+        } catch (ExitException) {
+        }
 
         $this->assertEquals($GLOBALS['conn_error'], '#42 Cannot log in to the MySQL server');
     }
@@ -848,6 +877,10 @@ class AuthenticationCookieTest extends AbstractNetworkTestCase
             ->onlyMethods(['showLoginForm'])
             ->getMock();
 
+        $this->object->expects($this->exactly(1))
+            ->method('showLoginForm')
+            ->willThrowException(new ExitException());
+
         $dbi = $this->getMockBuilder(DatabaseInterface::class)
             ->disableOriginalConstructor()
             ->getMock();
@@ -866,7 +899,10 @@ class AuthenticationCookieTest extends AbstractNetworkTestCase
             ['Cache-Control: no-store, no-cache, must-revalidate'],
             ['Pragma: no-cache'],
         );
-        $this->object->showFailure('');
+        try {
+            $this->object->showFailure('');
+        } catch (ExitException) {
+        }
 
         $this->assertEquals($GLOBALS['conn_error'], 'Cannot log in to the MySQL server');
     }
diff --git a/test/classes/Plugins/Auth/AuthenticationHttpTest.php b/test/classes/Plugins/Auth/AuthenticationHttpTest.php
index e1693cd872..d805e825d8 100644
--- a/test/classes/Plugins/Auth/AuthenticationHttpTest.php
+++ b/test/classes/Plugins/Auth/AuthenticationHttpTest.php
@@ -314,7 +314,7 @@ class AuthenticationHttpTest extends AbstractNetworkTestCase
 
         $result = ob_get_clean();
 
-        $this->assertInstanceOf(ExitException::class, $throwable ?? null);
+        $this->assertInstanceOf(ExitException::class, $throwable);
 
         $this->assertIsString($result);
 
@@ -326,15 +326,20 @@ class AuthenticationHttpTest extends AbstractNetworkTestCase
             ->getMock();
 
         $this->object->expects($this->exactly(2))
-            ->method('authForm');
+            ->method('authForm')
+            ->willThrowException(new ExitException());
         // case 2
         $GLOBALS['cfg']['Server']['host'] = 'host';
         $GLOBALS['errno'] = 1045;
 
-        $this->object->showFailure('');
+        try {
+            $this->object->showFailure('');
+        } catch (ExitException) {
+        }
 
         // case 3
         $GLOBALS['errno'] = 1043;
+        $this->expectException(ExitException::class);
         $this->object->showFailure('');
     }
 }
diff --git a/test/classes/Plugins/Auth/AuthenticationSignonTest.php b/test/classes/Plugins/Auth/AuthenticationSignonTest.php
index 28e4a9678e..e81eb2ba78 100644
--- a/test/classes/Plugins/Auth/AuthenticationSignonTest.php
+++ b/test/classes/Plugins/Auth/AuthenticationSignonTest.php
@@ -67,7 +67,7 @@ class AuthenticationSignonTest extends AbstractNetworkTestCase
 
         $result = ob_get_clean();
 
-        $this->assertInstanceOf(ExitException::class, $throwable ?? null);
+        $this->assertInstanceOf(ExitException::class, $throwable);
 
         $this->assertIsString($result);
 
@@ -229,9 +229,13 @@ class AuthenticationSignonTest extends AbstractNetworkTestCase
             ->getMock();
 
         $this->object->expects($this->exactly(1))
-            ->method('showLoginForm');
+            ->method('showLoginForm')
+            ->willThrowException(new ExitException());
 
-        $this->object->showFailure('empty-denied');
+        try {
+            $this->object->showFailure('empty-denied');
+        } catch (ExitException) {
+        }
 
         $this->assertEquals(
             'Login without a password is forbidden by configuration (see AllowNoPassword)',
@@ -250,9 +254,13 @@ class AuthenticationSignonTest extends AbstractNetworkTestCase
             ->getMock();
 
         $this->object->expects($this->exactly(1))
-            ->method('showLoginForm');
+            ->method('showLoginForm')
+            ->willThrowException(new ExitException());
 
-        $this->object->showFailure('allow-denied');
+        try {
+            $this->object->showFailure('allow-denied');
+        } catch (ExitException) {
+        }
 
         $this->assertEquals('Access denied!', $_SESSION['PMA_single_signon_error_message']);
     }
@@ -268,11 +276,15 @@ class AuthenticationSignonTest extends AbstractNetworkTestCase
             ->getMock();
 
         $this->object->expects($this->exactly(1))
-            ->method('showLoginForm');
+            ->method('showLoginForm')
+            ->willThrowException(new ExitException());
 
         $GLOBALS['cfg']['LoginCookieValidity'] = '1440';
 
-        $this->object->showFailure('no-activity');
+        try {
+            $this->object->showFailure('no-activity');
+        } catch (ExitException) {
+        }
 
         $this->assertEquals(
             'You have been automatically logged out due to inactivity of'
@@ -293,7 +305,8 @@ class AuthenticationSignonTest extends AbstractNetworkTestCase
             ->getMock();
 
         $this->object->expects($this->exactly(1))
-            ->method('showLoginForm');
+            ->method('showLoginForm')
+            ->willThrowException(new ExitException());
 
         $dbi = $this->getMockBuilder(DatabaseInterface::class)
             ->disableOriginalConstructor()
@@ -305,7 +318,10 @@ class AuthenticationSignonTest extends AbstractNetworkTestCase
 
         $GLOBALS['dbi'] = $dbi;
 
-        $this->object->showFailure('');
+        try {
+            $this->object->showFailure('');
+        } catch (ExitException) {
+        }
 
         $this->assertEquals('error&lt;123&gt;', $_SESSION['PMA_single_signon_error_message']);
     }
@@ -322,7 +338,8 @@ class AuthenticationSignonTest extends AbstractNetworkTestCase
             ->getMock();
 
         $this->object->expects($this->exactly(1))
-            ->method('showLoginForm');
+            ->method('showLoginForm')
+            ->willThrowException(new ExitException());
 
         $dbi = $this->getMockBuilder(DatabaseInterface::class)
             ->disableOriginalConstructor()
@@ -334,7 +351,10 @@ class AuthenticationSignonTest extends AbstractNetworkTestCase
 
         $GLOBALS['dbi'] = $dbi;
 
-        $this->object->showFailure('');
+        try {
+            $this->object->showFailure('');
+        } catch (ExitException) {
+        }
 
         $this->assertEquals('Cannot log in to the MySQL server', $_SESSION['PMA_single_signon_error_message']);
     }