diff --git a/.travis.yml b/.travis.yml
index 6d2d4e2..e4f850e 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,14 +1,11 @@
 language: php
 php:
-  - '5.6'
-  - '7.0'
   - '7.1'
   - '7.2'
   - hhvm
 
 matrix:
   allow_failures:
-    - php: 5.6
     - php: hhvm
   fast_finish: true
 
diff --git a/README.md b/README.md
index 422895e..4e6f8b3 100644
--- a/README.md
+++ b/README.md
@@ -18,11 +18,13 @@ or add the package to your `composer.json`
 ```json
 {
     "require": {
-        "peppeocchi/php-cron-scheduler": "2.*"
+        "peppeocchi/php-cron-scheduler": "3.*"
     }
 }
 ```
 
+Scheduler V3 requires php >= 7.1, please use the [v2 branch](https://github.com/peppeocchi/php-cron-scheduler/tree/v2.x) for php versions < 7.1.
+
 ## How it works
 
 Create a `scheduler.php` file in the root your project with the following content.
@@ -125,7 +127,7 @@ $scheduler->call(
 There are a few methods to help you set the execution time of your schedules.
 If you don't call any of this method, the job will run every minute (* * * * *).
 
-- `at` - This method accepts any expression supported by [mtdowling/cron-expression](https://github.com/mtdowling/cron-expression)
+- `at` - This method accepts any expression supported by [dragonmantank/cron-expression](https://github.com/dragonmantank/cron-expression)
     ```php
     $scheduler->php('script.php')->at('* * * * *');
     ```
diff --git a/composer.json b/composer.json
index d8a6cd5..4d757ee 100644
--- a/composer.json
+++ b/composer.json
@@ -17,8 +17,8 @@
     ],
     "minimum-stability": "dev",
     "require": {
-        "php": ">=5.5.9",
-        "mtdowling/cron-expression": "~1.0"
+        "php": "^7.1",
+        "dragonmantank/cron-expression": "^2.3"
     },
     "require-dev": {
         "phpunit/phpunit": "~5.7",
diff --git a/src/GO/Traits/Interval.php b/src/GO/Traits/Interval.php
index cb435a5..c80a4d9 100644
--- a/src/GO/Traits/Interval.php
+++ b/src/GO/Traits/Interval.php
@@ -413,6 +413,6 @@ private function validateCronRange($value, $min, $max)
             );
         }
 
-        return $value;
+        return (int) $value;
     }
 }