diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 2620463..75c5ab7 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -5,6 +5,9 @@ jobs:
     strategy:
       matrix:
         include:
+          - php: '7.1'
+          - php: '7.2'
+          - php: '7.3'
           - php: '7.4'
           - php: '8.0'
           - php: '8.1'
diff --git a/composer.json b/composer.json
index be5fb18..57ad67c 100644
--- a/composer.json
+++ b/composer.json
@@ -27,7 +27,7 @@
     "source": "https://github.com/miladrahimi/phpcontainer/issues"
   },
   "require": {
-    "php": ">=7.4",
+    "php": ">=7.1",
     "psr/container": "^2.0"
   },
   "autoload": {
diff --git a/src/Container.php b/src/Container.php
index ba40e6a..aeb08be 100644
--- a/src/Container.php
+++ b/src/Container.php
@@ -20,7 +20,7 @@ class Container implements ContainerInterface
      *
      * @var Transient[]|Singleton[]
      */
-    private array $repository = [];
+    private $repository = [];
 
     /**
      * Empty the container
diff --git a/tests/ContainerTest.php b/tests/ContainerTest.php
index 37dd1fb..0ad862c 100644
--- a/tests/ContainerTest.php
+++ b/tests/ContainerTest.php
@@ -139,6 +139,8 @@ public function test_prototype_callable_binding_with_no_parameter()
 
         $t1 = $this->container->get('time');
 
+        for ($i = 0; $i < 1000; $i++) sleep(0);
+
         $t2 = $this->container->get('time');
 
         $this->assertNotEquals($t1, $t2);