diff --git a/demo/auto/AutoValue_Address.php b/demo/auto/AutoValue_Address.php
index d5a16ca..6e7e144 100644
--- a/demo/auto/AutoValue_Address.php
+++ b/demo/auto/AutoValue_Address.php
@@ -6,7 +6,7 @@
  */
 final class AutoValue_Address extends Address
 {
-    /** @var array */
+    /** @var string[] */
     private $lines;
     /** @var ?string */
     private $city;
@@ -64,6 +64,7 @@ public function toBuilder(): \AutoValue\Demo\AddressBuilder
     public function withLines(string ...$lines): \AutoValue\Demo\Address
     {
         $result = clone $this;
+        unset($result->__memoized);
         $result->lines = $lines;
         return $result;
     }
@@ -71,6 +72,7 @@ public function withLines(string ...$lines): \AutoValue\Demo\Address
     public function withCountry(string $country): \AutoValue\Demo\Address
     {
         $result = clone $this;
+        unset($result->__memoized);
         $result->country = $country;
         return $result;
     }
diff --git a/demo/src/Address.php b/demo/src/Address.php
index a050c43..5d1472d 100644
--- a/demo/src/Address.php
+++ b/demo/src/Address.php
@@ -13,6 +13,9 @@ public static function builder(): AddressBuilder
 
     public abstract function toBuilder(): AddressBuilder;
 
+    /**
+     * @return string[]
+     */
     public abstract function lines(): array;
 
     public abstract function withLines(string ...$lines): self;
diff --git a/src/Property.php b/src/Property.php
index 0b21c70..5032795 100644
--- a/src/Property.php
+++ b/src/Property.php
@@ -1,6 +1,9 @@
 <?php
 namespace AutoValue;
 
+use phpDocumentor\Reflection\Type;
+use Roave\BetterReflection\Reflection\ReflectionMethod;
+use Roave\BetterReflection\Reflection\ReflectionProperty;
 use Roave\BetterReflection\Reflection\ReflectionType;
 
 /**
@@ -8,10 +11,11 @@
  */
 class Property
 {
-    public static function named(string $name): self
+    public static function fromAccessorMethod(string $propertyName, ReflectionMethod $accessorMethod): self
     {
         $property = new self;
-        $property->name = $name;
+        $property->name = $propertyName;
+        $property->accessorMethod = $accessorMethod;
         return $property;
     }
 
@@ -20,26 +24,38 @@ public function name(): string
         return $this->name;
     }
 
-    public function type(): ?ReflectionType
+    public function phpType(): ?ReflectionType
     {
-        return $this->type;
+        if (!$this->phpType) {
+            $this->phpType = $this->accessorMethod->getReturnType();
+        }
+        return $this->phpType;
     }
 
-    public function withType(?ReflectionType $type): self
+    public function docBlockType(): string
     {
-        $result = clone $this;
-        $result->type = $type;
-        return $result;
+        if (!isset($this->docBlockType)) {
+            $docBlockTypes = $this->accessorMethod->getDocBlockReturnTypes();
+            $this->docBlockType = $docBlockTypes
+                ? \implode('|', $docBlockTypes)
+                : ($this->phpType()
+                    ? generateTypeHint($this->phpType(), $this->accessorMethod->getDeclaringClass())
+                    : 'mixed'
+                );
+        }
+        return $this->docBlockType;
     }
 
     public function isRequired(): bool
     {
-        return $this->type && !$this->type->allowsNull();
+        return $this->phpType() && !$this->phpType()->allowsNull();
     }
 
     private $name;
+    /** @var ReflectionMethod */
+    private $accessorMethod;
     /** @var ReflectionType|null */
-    private $type;
+    private $phpType;
 
     private function __construct()
     {
diff --git a/src/ValueClass/AccessorMethodProcessor.php b/src/ValueClass/AccessorMethodProcessor.php
index d287396..50ef081 100644
--- a/src/ValueClass/AccessorMethodProcessor.php
+++ b/src/ValueClass/AccessorMethodProcessor.php
@@ -29,7 +29,7 @@ public function inferProperties(ReflectionMethodCollection $matchedMethods): Pro
         $templateUsesPrefixes = self::templateUsesPrefixes($matchedMethods);
         return $matchedMethods->reduce(PropertyCollection::create(), function (PropertyCollection $properties, ReflectionMethod $method) use ($templateUsesPrefixes) {
             $propertyName = self::getPropertyName($templateUsesPrefixes, $method);
-            $property = Property::named($propertyName)->withType($method->getReturnType());
+            $property = Property::fromAccessorMethod($propertyName, $method);
             return $properties->withProperty($property);
         });
     }
diff --git a/src/ValueClass/ValueClassGenerator.php b/src/ValueClass/ValueClassGenerator.php
index 0cd2815..3cda897 100644
--- a/src/ValueClass/ValueClassGenerator.php
+++ b/src/ValueClass/ValueClassGenerator.php
@@ -18,13 +18,8 @@ public function generateClass(ReflectionClass $baseClass, PropertyCollection $pr
     {
         // todo include type in properties constant
         $propertyDeclarations = \implode("\n", $properties->map(function (Property $property) use ($baseClass) {
-            if ($property->type()) {
-                $type = generateTypeHint($property->type(), $baseClass);
-            } else {
-                $type = 'mixed';
-            }
             return <<<THEPHP
-    /** @var $type */
+    /** @var {$property->docBlockType()} */
     private \${$property->name()};
 THEPHP;
         }));
diff --git a/src/ValueEquals/EqualsMethodProcessor.php b/src/ValueEquals/EqualsMethodProcessor.php
index 55cee84..3434e26 100644
--- a/src/ValueEquals/EqualsMethodProcessor.php
+++ b/src/ValueEquals/EqualsMethodProcessor.php
@@ -50,25 +50,25 @@ private function generateMethodBody(
         string $valueParam,
         PropertyCollection $properties
     ): string {
-        $typedProperties = $properties->filter(function (Property $property) { return $property->type() !== null; });
-        $arrayProperties = $typedProperties->filter(function (Property $property) { return (string)$property->type() === 'array'; });
-        $classProperties = $typedProperties->filter(function (Property $property) { return isClass($property->type()); });
+        $typedProperties = $properties->filter(function (Property $property) { return $property->phpType() !== null; });
+        $arrayProperties = $typedProperties->filter(function (Property $property) { return (string)$property->phpType() === 'array'; });
+        $classProperties = $typedProperties->filter(function (Property $property) { return isClass($property->phpType()); });
         $valueObjectProperties = $classProperties->filter(function (Property $property) use ($templateClass) {
             return $this->isValueObject($templateClass, $property);
         });
         $mixedProperties = $properties->filter(function (Property $property) {
-            return $property->type() === null
-                || (string)$property->type() === 'object'
-                || (string)$property->type() === 'iterable'
-                || (string)$property->type() === 'callable';
+            return $property->phpType() === null
+                || (string)$property->phpType() === 'object'
+                || (string)$property->phpType() === 'iterable'
+                || (string)$property->phpType() === 'callable';
         });
 
         $testsForTypedProperties = \array_merge(
             ["\${$valueParam} instanceof self"],
 
             $typedProperties
-                ->filter(function (Property $property) { return !isClass($property->type()); })
-                ->filter(function (Property $property) { return (string)$property->type() !== 'array'; })
+                ->filter(function (Property $property) { return !isClass($property->phpType()); })
+                ->filter(function (Property $property) { return (string)$property->phpType() !== 'array'; })
                 ->mapPropertyNames(function (string $propertyName) use ($valueParam) {
                     return "\$this->$propertyName === \${$valueParam}->$propertyName";
                 }),
@@ -137,7 +137,7 @@ private function generateMethodBody(
 
     private function isValueObject(ReflectionClass $templateClass, Property $property): bool
     {
-        $reflectionClass = getClass($templateClass, $property->type());
+        $reflectionClass = getClass($templateClass, $property->phpType());
         return $reflectionClass->hasMethod('equals')
             && $this->matchMethod($reflectionClass->getMethod('equals'));
     }
diff --git a/src/functions.php b/src/functions.php
index c62f8bb..607a3b3 100644
--- a/src/functions.php
+++ b/src/functions.php
@@ -35,12 +35,12 @@ function generateParameters(array $reflectionParameters): string
     }, $reflectionParameters));
 }
 
-function generateReturnTypeHint(?ReflectionType $returnType, ?ReflectionClass $declaringClass): string
+function generateReturnTypeHint(?ReflectionType $returnType, ReflectionClass $declaringClass): string
 {
     return $returnType === null ? '' : ': ' . generateTypeHint($returnType, $declaringClass);
 }
 
-function generateTypeHint(ReflectionType $type, ?ReflectionClass $declaringClass): string
+function generateTypeHint(ReflectionType $type, ReflectionClass $declaringClass): string
 {
     $prefix = $type->allowsNull() ? '?' : '';
     $normalizedType = (string)$type === 'self'