diff --git a/composer.json b/composer.json
index 3d9808a..ce2cde1 100644
--- a/composer.json
+++ b/composer.json
@@ -53,7 +53,7 @@
         "phpunit/phpunit":             "^6.2 || ^7.0",
         "symfony/var-dumper":          "^3.3",
         "phpspec/prophecy":            "^1.7",
-        "phpstan/phpstan":             "^0.12.5",
+        "phpstan/phpstan":             "^0.12.5 || ^1.0.0",
         "squizlabs/php_codesniffer":   "^3.0",
         "howyi/conv-test-suite":       "dev-master",
         "php-coveralls/php-coveralls": "^2.2"