diff --git a/composer.json b/composer.json
index 7c4480773b..08af134c98 100644
--- a/composer.json
+++ b/composer.json
@@ -104,6 +104,7 @@
         "phpmyadmin/coding-standard": "^3.0.0",
         "phpstan/extension-installer": "^1.1",
         "phpstan/phpstan": "^1.4.8",
+        "phpstan/phpstan-deprecation-rules": "^1.0",
         "phpstan/phpstan-phpunit": "^1.0",
         "phpstan/phpstan-webmozart-assert": "^1.0",
         "phpunit/phpunit": "^8.5.16 || ^9.6",
diff --git a/libraries/classes/Navigation/NavigationTree.php b/libraries/classes/Navigation/NavigationTree.php
index df625a7ba7..636ccfd386 100644
--- a/libraries/classes/Navigation/NavigationTree.php
+++ b/libraries/classes/Navigation/NavigationTree.php
@@ -682,12 +682,12 @@ class NavigationTree
             foreach ($node->children as $child) {
                 $prefixPos = false;
                 foreach ($separators as $separator) {
-                    $sepPos = mb_strpos((string) $child->name, $separator);
+                    $sepPos = mb_strpos($child->name, $separator);
                     if (
-                        $sepPos == false
-                        || $sepPos == mb_strlen($child->name)
-                        || $sepPos == 0
+                        $sepPos === false
+                        || $sepPos === 0
                         || ($prefixPos !== false && $sepPos >= $prefixPos)
+                        || $sepPos === mb_strlen($child->name)
                     ) {
                         continue;
                     }
diff --git a/libraries/classes/Utils/ForeignKey.php b/libraries/classes/Utils/ForeignKey.php
index 165c02c3e7..e85b2af8ca 100644
--- a/libraries/classes/Utils/ForeignKey.php
+++ b/libraries/classes/Utils/ForeignKey.php
@@ -30,7 +30,7 @@ final class ForeignKey
                 $dbi->fetchValue('SELECT @@ndb_version_string') ?: ''
             );
             if (substr($ndbver, 0, 4) === 'ndb-') {
-                $ndbver = substr($ndbver, 4);
+                $ndbver = (string) substr($ndbver, 4);
             }
 
             return version_compare($ndbver, '7.3', '>=');
diff --git a/phpstan-baseline.neon b/phpstan-baseline.neon
index 77a705c932..a397e806f7 100644
--- a/phpstan-baseline.neon
+++ b/phpstan-baseline.neon
@@ -8920,6 +8920,11 @@ parameters:
 			count: 1
 			path: libraries/classes/UserPreferences.php
 
+		-
+			message: "#^Cannot access offset non\\-falsy\\-string on array\\{\\}\\|float\\|int\\|non\\-falsy\\-string\\.$#"
+			count: 1
+			path: libraries/classes/Util.php
+
 		-
 			message: "#^Cannot cast mixed to string\\.$#"
 			count: 1
diff --git a/psalm-baseline.xml b/psalm-baseline.xml
index 95b605ffdd..8ab678189e 100644
--- a/psalm-baseline.xml
+++ b/psalm-baseline.xml
@@ -8565,8 +8565,7 @@
       <code>(int) $GLOBALS['cfg']['NavigationTreeDisplayDbFilterMinimum']</code>
       <code>(int) $GLOBALS['cfg']['NavigationTreeDisplayItemFilterMinimum']</code>
     </RedundantCast>
-    <RedundantCastGivenDocblockType occurrences="6">
-      <code>(string) $child-&gt;name</code>
+    <RedundantCastGivenDocblockType occurrences="5">
       <code>(string) $child-&gt;name</code>
       <code>(string) $key</code>
       <code>(string) $key</code>
@@ -15537,9 +15536,6 @@
     </MixedInferredReturnType>
   </file>
   <file src="test/classes/Http/Factory/ServerRequestFactoryTest.php">
-    <DeprecatedMethod occurrences="1">
-      <code>setMethods</code>
-    </DeprecatedMethod>
     <MixedArgument occurrences="1">
       <code>$serverRequest</code>
     </MixedArgument>
diff --git a/test/classes/Http/Factory/ServerRequestFactoryTest.php b/test/classes/Http/Factory/ServerRequestFactoryTest.php
index 6c4880df93..c356c06347 100644
--- a/test/classes/Http/Factory/ServerRequestFactoryTest.php
+++ b/test/classes/Http/Factory/ServerRequestFactoryTest.php
@@ -130,7 +130,7 @@ class ServerRequestFactoryTest extends AbstractTestCase
         $_SERVER['HTTP_HOST'] = 'phpmyadmin.local';
 
         $creator = $this->getMockBuilder(ServerRequestFactory::class)
-            ->setMethods(['getallheaders'])
+            ->onlyMethods(['getallheaders'])
             ->getMock();
 
         $creator