diff --git a/composer.json b/composer.json
index 384df3c..7b86c6b 100644
--- a/composer.json
+++ b/composer.json
@@ -19,6 +19,7 @@
     "autoload": {
         "psr-4": {
             "gapple\\StructuredFields\\": "src/",
+            "gapple\\StructuredFields\\PHPStan\\": "phpstan-extension/src/",
             "gapple\\Tests\\StructuredFields\\": "tests/"
         }
     },
diff --git a/phpstan-extension/src/DynamicPropertiesClassReflectionExtension.php b/phpstan-extension/src/DynamicPropertiesClassReflectionExtension.php
new file mode 100644
index 0000000..3909bd3
--- /dev/null
+++ b/phpstan-extension/src/DynamicPropertiesClassReflectionExtension.php
@@ -0,0 +1,29 @@
+<?php
+
+namespace gapple\StructuredFields\PHPStan;
+
+use gapple\StructuredFields\Dictionary;
+use gapple\StructuredFields\Parameters;
+use PHPStan\Reflection\ClassReflection;
+use PHPStan\Reflection\PropertiesClassReflectionExtension;
+use PHPStan\Reflection\PropertyReflection;
+
+class DynamicPropertiesClassReflectionExtension implements PropertiesClassReflectionExtension
+{
+    public function hasProperty(ClassReflection $classReflection, string $propertyName): bool
+    {
+        return (
+                $classReflection->is(Dictionary::class)
+                || $classReflection->is(Parameters::class)
+            )
+            && preg_match('/^[a-z*][a-z0-9.*_-]*$/', $propertyName);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getProperty(ClassReflection $classReflection, string $propertyName): PropertyReflection
+    {
+        return new DynamicPropertyReflection($classReflection);
+    }
+}
diff --git a/phpstan-extension/src/DynamicPropertyReflection.php b/phpstan-extension/src/DynamicPropertyReflection.php
new file mode 100644
index 0000000..316b3f9
--- /dev/null
+++ b/phpstan-extension/src/DynamicPropertyReflection.php
@@ -0,0 +1,87 @@
+<?php
+
+namespace gapple\StructuredFields\PHPStan;
+
+use PHPStan\Reflection\ClassReflection;
+use PHPStan\Reflection\PropertyReflection;
+use PHPStan\TrinaryLogic;
+use PHPStan\Type\MixedType;
+use PHPStan\Type\Type;
+
+class DynamicPropertyReflection implements PropertyReflection
+{
+    /**
+     * @var ClassReflection
+     */
+    private $classReflection;
+
+    public function __construct(ClassReflection $classReflection)
+    {
+        $this->classReflection = $classReflection;
+    }
+
+    public function getDeclaringClass(): \PHPStan\Reflection\ClassReflection
+    {
+        return $this->classReflection;
+    }
+
+    public function isStatic(): bool
+    {
+        return false;
+    }
+
+    public function isPrivate(): bool
+    {
+        return false;
+    }
+
+    public function isPublic(): bool
+    {
+        return true;
+    }
+
+    public function getDocComment(): ?string
+    {
+        return null;
+    }
+
+    public function getReadableType(): Type
+    {
+        return new MixedType();
+    }
+
+    public function getWritableType(): Type
+    {
+        return new MixedType();
+    }
+
+    public function canChangeTypeAfterAssignment(): bool
+    {
+        return true;
+    }
+
+    public function isReadable(): bool
+    {
+        return true;
+    }
+
+    public function isWritable(): bool
+    {
+        return true;
+    }
+
+    public function isDeprecated(): TrinaryLogic
+    {
+        return TrinaryLogic::createMaybe();
+    }
+
+    public function getDeprecatedDescription(): ?string
+    {
+        return null;
+    }
+
+    public function isInternal(): TrinaryLogic
+    {
+        return TrinaryLogic::createMaybe();
+    }
+}
diff --git a/phpstan.neon.dist b/phpstan.neon.dist
index 0cc958d..1a2a04f 100644
--- a/phpstan.neon.dist
+++ b/phpstan.neon.dist
@@ -8,10 +8,6 @@ parameters:
         - src
         - tests
 
-    universalObjectCratesClasses:
-        - gapple\StructuredFields\Dictionary
-        - gapple\StructuredFields\Parameters
-
     featureToggles:
       readOnlyByPhpDoc: true
 
@@ -19,3 +15,8 @@ parameters:
         -
             message: '#Unreachable statement - code above always terminates.#'
             path: src/TupleTrait.php
+
+services:
+  - class: gapple\StructuredFields\PHPStan\DynamicPropertiesClassReflectionExtension
+    tags:
+      - phpstan.broker.propertiesClassReflectionExtension