diff --git a/phpstan.neon b/phpstan.neon
index d7f8277..eab1b77 100644
--- a/phpstan.neon
+++ b/phpstan.neon
@@ -1,4 +1,4 @@
 parameters:
-	level: 6
+	level: 7
 	paths:
 		- src
diff --git a/src/Main.php b/src/Main.php
index 305a2ad..6f9a96c 100644
--- a/src/Main.php
+++ b/src/Main.php
@@ -51,7 +51,7 @@ private function findEntries(Finder $finder): array
         foreach ($finder as $file) {
             try {
                 $reflections = PhpReader::parseFile(
-                    realpath($this->directory),
+                    (string)realpath($this->directory),
                     $file->getRealPath(),
                     $this->options
                 );
diff --git a/src/Php/PhpAccessModifier.php b/src/Php/PhpAccessModifier.php
index 3e72f0b..7c8f8c6 100644
--- a/src/Php/PhpAccessModifier.php
+++ b/src/Php/PhpAccessModifier.php
@@ -24,15 +24,15 @@ final class PhpAccessModifier
     public function __construct(ClassConst|Property|ClassMethod|Param $stmt)
     {
         if ($stmt instanceof Param) {
-            $this->public = boolval($stmt->flags & Class_::MODIFIER_PUBLIC);
-            $this->protected = boolval($stmt->flags & Class_::MODIFIER_PROTECTED);
-            $this->private = boolval($stmt->flags & Class_::MODIFIER_PRIVATE);
+            $this->public = (bool)($stmt->flags & Class_::MODIFIER_PUBLIC);
+            $this->protected = (bool)($stmt->flags & Class_::MODIFIER_PROTECTED);
+            $this->private = (bool)($stmt->flags & Class_::MODIFIER_PRIVATE);
         } else {
             $this->public = $stmt->isPublic();
             $this->protected = $stmt->isProtected();
             $this->private = $stmt->isPrivate();
-            $this->static = $stmt->isStatic();
             if ($stmt instanceof ClassMethod) {
+                $this->static = $stmt->isStatic();
                 $this->abstract = $stmt->isAbstract();
             }
         }
diff --git a/src/Php/PhpClass.php b/src/Php/PhpClass.php
index b7f0e6f..e9e2607 100644
--- a/src/Php/PhpClass.php
+++ b/src/Php/PhpClass.php
@@ -4,6 +4,7 @@
 
 namespace Smeghead\PhpClassDiagram\Php;
 
+use PhpParser\Node;
 use PhpParser\Node\Name\FullyQualified;
 use PhpParser\Node\Stmt\{
     Namespace_,
@@ -21,14 +22,14 @@
 
 final class PhpClass
 {
-    /** @var string[] directory parts */
+    /** @var list<string> directory parts */
     private array $dirs;
     private ClassLike $syntax;
-    /** @var \PhpParser\Node[] */
+    /** @var list<Node> */
     private array $full;
 
     /**
-     * @param \PhpParser\Node[] $full
+     * @param list<Node> $full
      */
     public function __construct(string $filename, ClassLike $syntax, array $full)
     {
@@ -36,7 +37,8 @@ public function __construct(string $filename, ClassLike $syntax, array $full)
         if ($relativePath === '.') {
             $dirs = [];
         } else {
-            $dirs = preg_split('/[\\\\\/]/', $relativePath);
+            /** @var list<string> $dirs */
+            $dirs = (array)preg_split('/[\\\\\/]/', $relativePath);
         }
         $this->dirs = $dirs;
         $this->syntax = $syntax;
@@ -124,7 +126,7 @@ public function getUses(): array
     }
 
     /**
-     * @param \PhpParser\Node[] $stmts Stmts
+     * @param list<Node> $stmts Stmts
      * @param PhpType[] $uses
      * @return PhpType[]
      */
@@ -180,7 +182,7 @@ public function getExtends(): array
                 $extends[] = new PhpType(
                     array_slice($extend->parts, 0, count($extend->parts) - 1),
                     '',
-                    end($extend->parts)
+                    (string)end($extend->parts)
                 );
             }
         }
@@ -191,7 +193,7 @@ public function getExtends(): array
                     $extends[] = new PhpType(
                         array_slice($implement->parts, 0, count($implement->parts) - 1),
                         '',
-                        end($implement->parts)
+                        (string)end($implement->parts)
                     );
                 }
             }
@@ -218,16 +220,21 @@ public function getEnumCases(): array
 
     public function getDescription(): string
     {
-        $doc = new PhpDocComment($this->syntax);
-        return $doc->getDescription();
+        return (new PhpDocComment($this->syntax))
+            ->getDescription();
     }
 
     /**
-     * @return PhpType[] using types.
+     * @return list<PhpType>
      */
     public function getUsingTypes(): array
     {
         $finder = new FindUsePhpTypes($this->syntax);
-        return array_map(fn(FullyQualified $x) => new PhpType(array_slice($x->parts, 0, count($x->parts) - 1), '', end($x->parts)), $finder->collectTypes());
+        return array_map(
+            fn(FullyQualified $x) => new PhpType(
+                array_slice($x->parts, 0, count($x->parts) - 1), '', (string)end($x->parts)
+            ),
+            $finder->collectTypes()
+        );
     }
 }
diff --git a/src/Php/PhpMethod.php b/src/Php/PhpMethod.php
index 62f36f8..97547cc 100644
--- a/src/Php/PhpMethod.php
+++ b/src/Php/PhpMethod.php
@@ -22,8 +22,16 @@ final class PhpMethod
     public function __construct(ClassMethod $method, PhpClass $class)
     {
         $params = array_map(function (Param $x) use ($class, $method) {
-            $type = PhpTypeExpression::buildByMethodParam($x, $class->getNamespace(), $method, $x->var->name, $class->getUses());
-            return new PhpMethodParameter($x->var->name, $type);
+            /** @var string $varName */
+            $varName = $x->var->name; /** @phpstan-ignore-line */
+            $type = PhpTypeExpression::buildByMethodParam(
+                $x,
+                $class->getNamespace(),
+                $method,
+                $varName,
+                $class->getUses()
+            );
+            return new PhpMethodParameter($varName, $type);
         }, $method->getParams());
         $this->name = $method->name->toString();
         $this->type = $this->getTypeFromMethod($method, $class);
diff --git a/src/Php/PhpProperty.php b/src/Php/PhpProperty.php
index d1852f3..557afa2 100644
--- a/src/Php/PhpProperty.php
+++ b/src/Php/PhpProperty.php
@@ -32,8 +32,16 @@ public static function buildByProperty(Property $p, PhpClass $class): self
     public static function buildByParam(Param $param, ClassMethod $method, PhpClass $class): self
     {
         $instance = new self();
-        $instance->name = $param->var->name;
-        $instance->type = PhpTypeExpression::buildByMethodParam($param, $class->getNamespace(), $method, $param->var->name, $class->getUses());
+        /** @var string $varName */
+        $varName = $param->var->name; // @phpstan-ignore-line
+        $instance->name = $varName;
+        $instance->type = PhpTypeExpression::buildByMethodParam(
+            $param,
+            $class->getNamespace(),
+            $method,
+            $varName,
+            $class->getUses()
+        );
         $instance->accessModifier = new PhpAccessModifier($param);
         return $instance;
     }
diff --git a/src/Php/PhpReader.php b/src/Php/PhpReader.php
index cb57161..c6d8be3 100644
--- a/src/Php/PhpReader.php
+++ b/src/Php/PhpReader.php
@@ -31,7 +31,7 @@ public function getInfo(): PhpClass
      */
     public static function parseFile(string $directory, string $filename, Options $options): array
     {
-        $code = file_get_contents($filename);
+        $code = (string)file_get_contents($filename);
 
         $targetVersion = match ($options->phpVersion()) {
             'php5' => ParserFactory::PREFER_PHP5,
diff --git a/src/Php/PhpTypeExpression.php b/src/Php/PhpTypeExpression.php
index ecbea1e..b3a1707 100644
--- a/src/Php/PhpTypeExpression.php
+++ b/src/Php/PhpTypeExpression.php
@@ -194,8 +194,16 @@ private function parseType(Property|Identifier|NullableType|Name|UnionType|Inter
                 }
             }
         }
+        /** @var list<string> $parts */
         $typeName = array_pop($parts);
-        return new PhpType($parts, empty($type) ? '' : $type->getType(), $typeName ?? '', null, $nullable);
+
+        return new PhpType(
+            namespace: $parts,
+            meta: empty($type) ? '' : $type->getType(),
+            name: $typeName ?? '',
+            alias: null,
+            nullable: $nullable
+        );
     }
 
     /**