diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0bae1d6..1990d95 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,7 +2,8 @@
 =====
 
 * (feature) Add `task-manager:run-worker` command as wrapper for Symfony messengers `consume` command.
-* (improvement) Default to limit of 5 messages in run worker command, if no other limit is given.
+* (improvement) Default to `limit` of 5 messages in run worker command, if no other limit is given.
+* (improvement) Validate unique task ids to a specific format.
 
 
 2.0.3
diff --git a/composer.json b/composer.json
index 188cc48..8c8d9b2 100644
--- a/composer.json
+++ b/composer.json
@@ -32,7 +32,8 @@
 		"21torr/janus": "^1.4.0",
 		"bamarni/composer-bin-plugin": "^1.8",
 		"roave/security-advisories": "dev-latest",
-		"symfony/phpunit-bridge": "^7.2"
+		"symfony/phpunit-bridge": "^7.2",
+		"symfony/translation-contracts": "^3.6"
 	},
 	"autoload": {
 		"psr-4": {
diff --git a/src/Exception/Task/InvalidTaskDefinitionException.php b/src/Exception/Task/InvalidTaskDefinitionException.php
new file mode 100644
index 0000000..5aeef02
--- /dev/null
+++ b/src/Exception/Task/InvalidTaskDefinitionException.php
@@ -0,0 +1,12 @@
+<?php declare(strict_types=1);
+
+namespace Torr\TaskManager\Exception\Task;
+
+use Torr\TaskManager\Exception\TaskManagerException;
+
+/**
+ * @final
+ */
+class InvalidTaskDefinitionException extends \InvalidArgumentException implements TaskManagerException
+{
+}
diff --git a/src/Task/TaskMetaData.php b/src/Task/TaskMetaData.php
index 5c0868a..7d106b1 100644
--- a/src/Task/TaskMetaData.php
+++ b/src/Task/TaskMetaData.php
@@ -3,6 +3,7 @@
 namespace Torr\TaskManager\Task;
 
 use Symfony\Component\String\Slugger\AsciiSlugger;
+use Torr\TaskManager\Exception\Task\InvalidTaskDefinitionException;
 
 use function Symfony\Component\String\u;
 
@@ -17,13 +18,28 @@ public function __construct (
 		public string $label,
 		public ?string $group = null,
 		public ?string $uniqueTaskId = null,
-	) {}
+	)
+	{
+		if (null !== $this->uniqueTaskId && !preg_match('~^[a-z0-9]+([.\\-_][a-z0-9]+)*$~', $this->uniqueTaskId))
+		{
+			throw new InvalidTaskDefinitionException(\sprintf(
+				"Invalid unique task id: '%s'",
+				$this->uniqueTaskId,
+			));
+		}
+	}
 
 	/**
 	 * Returns a unique key for this task
 	 */
 	public function getKey () : string
 	{
+		// these are validated to be safe, so we can keep using these
+		if (null !== $this->uniqueTaskId)
+		{
+			return $this->uniqueTaskId;
+		}
+
 		$slugger = new AsciiSlugger("en");
 		$key = u($this->label)->lower()->toString();
 
diff --git a/tests/Task/TaskMetaDataTest.php b/tests/Task/TaskMetaDataTest.php
new file mode 100644
index 0000000..b0d52cf
--- /dev/null
+++ b/tests/Task/TaskMetaDataTest.php
@@ -0,0 +1,60 @@
+<?php declare(strict_types=1);
+
+namespace Tests\Torr\TaskManager\Task;
+
+use PHPUnit\Framework\TestCase;
+use Torr\TaskManager\Exception\Task\InvalidTaskDefinitionException;
+use Torr\TaskManager\Task\TaskMetaData;
+
+/**
+ * @internal
+ */
+final class TaskMetaDataTest extends TestCase
+{
+	public static function provideValidUniqueTaskIds () : iterable
+	{
+		yield "plain" => ["test"];
+		yield "with dash" => ["a-b"];
+		yield "with underscore" => ["a-b_c"];
+		yield "all characters" => ["a-b_c.d"];
+		yield "numbers" => ["5"];
+		yield "numbers longer" => ["1-2-3-4"];
+	}
+
+	/**
+	 * @dataProvider provideValidUniqueTaskIds
+	 */
+	public function testValidUniqueTaskIds (string $uniqueTaskId) : void
+	{
+		$metadata = new TaskMetaData("Test", uniqueTaskId: $uniqueTaskId);
+		self::assertSame($uniqueTaskId, $metadata->getKey());
+	}
+
+	public static function provideInvalidUniqueTaskIds () : iterable
+	{
+		yield "empty" => [""];
+		yield "dash at the end" => ["test-"];
+		yield "dot at the end" => ["test."];
+		yield "underscore at the end" => ["test_"];
+		yield "dash at the beginning" => ["-test"];
+		yield "dot at the beginning" => ["_test"];
+		yield "underscore at the beginning" => [".test"];
+		yield "double dash" => ["a--b"];
+		yield "special characters" => ["a@b"];
+		yield "upper case characters" => ["aBc"];
+	}
+
+	/**
+	 * @dataProvider provideInvalidUniqueTaskIds
+	 */
+	public function testInvalidUniqueTaskIds (string $uniqueTaskId) : void
+	{
+		$this->expectException(InvalidTaskDefinitionException::class);
+		$this->expectExceptionMessage(\sprintf(
+			"Invalid unique task id: '%s'",
+			$uniqueTaskId,
+		));
+
+		new TaskMetaData("Test", uniqueTaskId: $uniqueTaskId);
+	}
+}