diff --git a/composer.json b/composer.json
index 112e134..8429338 100644
--- a/composer.json
+++ b/composer.json
@@ -11,6 +11,7 @@
   "license": "MIT",
   "require": {
     "php": "^7.1 || ^8.0",
+    "ext-json": "*",
     "giggsey/libphonenumber-for-php": "^7.0 || ^8.0"
   },
   "require-dev": {
diff --git a/src/PhoneNumber.php b/src/PhoneNumber.php
index f1aaf8b..396bbac 100644
--- a/src/PhoneNumber.php
+++ b/src/PhoneNumber.php
@@ -4,13 +4,14 @@
 
 namespace Brick\PhoneNumber;
 
+use JsonSerializable;
 use libphonenumber\NumberParseException;
 use libphonenumber\PhoneNumberUtil;
 
 /**
  * A phone number.
  */
-class PhoneNumber
+class PhoneNumber implements JsonSerializable
 {
     /**
      * The underlying PhoneNumber object from libphonenumber.
@@ -203,6 +204,14 @@ public function isEqualTo(PhoneNumber $phoneNumber): bool
         return $this->phoneNumber->equals($phoneNumber->phoneNumber);
     }
 
+    /**
+     * Required by interface JsonSerializable.
+     */
+    public function jsonSerialize(): string
+    {
+        return (string) $this;
+    }
+
     /**
      * Returns a string representation of this phone number in international E164 format.
      *
diff --git a/tests/PhoneNumberTest.php b/tests/PhoneNumberTest.php
index 575ab6a..7029849 100644
--- a/tests/PhoneNumberTest.php
+++ b/tests/PhoneNumberTest.php
@@ -585,4 +585,13 @@ public function providerIsEqualTo(): array
             ['+442079460585', '+442079460586', false],
         ];
     }
+
+    public function testJsonSerializable(): void
+    {
+        $data = [
+            'phoneNumber' => PhoneNumber::parse('0123000000', 'FR')
+        ];
+
+        self::assertSame('{"phoneNumber":"+33123000000"}', json_encode($data));
+    }
 }