diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 152cf58..9eb50a9 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -7,7 +7,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        php: ['7.0', '7.1', '7.2', '7.3', '7.4', '8.0']
+        php: ['7.1', '7.2', '7.3', '7.4', '8.0', '8.1']
     name: PHP ${{ matrix.php }}
     steps:
     - name: Checkout
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0bd03ba..3aa08aa 100755
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,16 @@
 # Changelog
 
+## [Unreleased]
+
+### Backward Compatibility Breaking Changes
+
+- Dropped support for PHP 7.0
+
+### Added
+
+- Support for PHP 8.1
+
+
 ## [3.0.0-rc2] - 2021-07-22
 
 ### Backward Compatibility Breaking Changes
diff --git a/composer.json b/composer.json
index 8d2c6cf..b29708d 100755
--- a/composer.json
+++ b/composer.json
@@ -6,7 +6,7 @@
     "homepage": "https://github.com/rlanvin/php-ip",
     "license": "MIT",
     "require": {
-        "php": ">=7.0",
+        "php": ">=7.1",
         "ext-gmp": "*"
     },
     "require-dev": {
@@ -22,4 +22,4 @@
             "PhpIP\\Tests\\": "tests/"
         }
     }
-}
\ No newline at end of file
+}
diff --git a/src/IPBlock.php b/src/IPBlock.php
index 189ea1c..b36b476 100644
--- a/src/IPBlock.php
+++ b/src/IPBlock.php
@@ -604,7 +604,7 @@ public function offsetGet($offset): IP
      *
      * {@inheritdoc}
      */
-    public function offsetSet($offset, $value)
+    public function offsetSet($offset, $value): void
     {
         throw new \LogicException('Setting IP in block is not supported');
     }
@@ -614,7 +614,7 @@ public function offsetSet($offset, $value)
      *
      * {@inheritdoc}
      */
-    public function offsetUnset($offset)
+    public function offsetUnset($offset): void
     {
         throw new \LogicException('Unsetting IP in block is not supported');
     }