diff --git a/composer.json b/composer.json
index 7f65c86c..5c527062 100644
--- a/composer.json
+++ b/composer.json
@@ -37,7 +37,7 @@
         "ext-posix": "*",
         "ext-mbstring": "*",
         "ext-curl": "*",
-        "ext-json": "*"
+        "ext-json": "*",
     },
     "require-dev": {
 		"phpunit/phpunit"	    : "6.5.13",
@@ -47,7 +47,8 @@
 		"squizlabs/php_codesniffer" : "3.3.2",
 		"phploc/phploc"             : "3.0.1",
 		"theseer/phpdox"            : "0.11.2",
-		"phpunit/php-invoker"       : "^2.0"
+		"phpunit/php-invoker"       : "1.1.4",
+		"ext-pcntl"		    : "*"
 	},
     "suggest": {
         "ext-bcmath": "*",