diff --git a/src/Type/Php/JsonThrowOnErrorDynamicReturnTypeExtension.php b/src/Type/Php/JsonThrowOnErrorDynamicReturnTypeExtension.php
index 127c34125b2..8337f9bf1e5 100644
--- a/src/Type/Php/JsonThrowOnErrorDynamicReturnTypeExtension.php
+++ b/src/Type/Php/JsonThrowOnErrorDynamicReturnTypeExtension.php
@@ -131,7 +131,7 @@ private function narrowTypeForJsonDecode(FuncCall $funcCall, Scope $scope): Type
 		}
 
 		// fallback type
-		if ($isArrayWithoutStdClass) {
+		if ($isArrayWithoutStdClass === true) {
 			return new MixedType(true, new ObjectType(stdClass::class));
 		}
 
@@ -164,7 +164,7 @@ private function isForceArrayWithoutStdClass(FuncCall $funcCall, Scope $scope):
 				// @see https://www.php.net/manual/en/json.constants.php#constant.json-object-as-array
 				$thirdArgValue = $args[3]->value;
 				$resolvedThirdArgValue = $this->resolveMaskValue($thirdArgValue, $scope);
-				if ($resolvedThirdArgValue & JSON_OBJECT_AS_ARRAY) {
+				if (($resolvedThirdArgValue & JSON_OBJECT_AS_ARRAY) !== 0) {
 					return true;
 				}
 			}
@@ -180,6 +180,9 @@ private function resolveConstantStringType(ConstantStringType $constantStringTyp
 		return ConstantTypeHelper::getTypeFromValue($decodedValue);
 	}
 
+	/**
+	 * @return mixed
+	 */
 	private function resolveMaskValue(Expr $expr, Scope $scope)
 	{
 		$thirdArgValueType = $scope->getType($expr);