diff --git a/src/Concern/GeneratesDefinition.php b/src/Concern/GeneratesDefinition.php
new file mode 100644
index 0000000..c5a2c47
--- /dev/null
+++ b/src/Concern/GeneratesDefinition.php
@@ -0,0 +1,51 @@
+<?php
+
+/**
+ * @file
+ * Contains Phagrancy\Concern\GeneratesDefinition
+ */
+
+namespace Phagrancy\Concern;
+
+use Phagrancy\Model\Entity;
+use Psr\Http\Message\UriInterface;
+
+/**
+ * Box JSON definition generator
+ *
+ * @package Phagrancy\Concern
+ */
+trait GeneratesDefinition
+{
+	public function __construct(Entity\Box $box, UriInterface $uri)
+	{
+		parent::__construct($this->generateDefinition($box, $uri));
+	}
+
+	public function generateDefinition(Entity\Box $box, UriInterface $uri)
+	{
+		$json = [
+			$this->nameKey => $box->path(),
+			'versions'     => []
+		];
+
+		foreach ($box->versions() as $version => $providers) {
+			if (empty($providers)) {
+				continue;
+			}
+			$versionedProviders = [];
+			foreach ($providers as $provider) {
+				$versionedProviders[] = [
+					'name' => (string)$provider,
+					'url'  => (string)$uri->withPath($this->resolveUriPath($box, $version, $provider))
+				];
+			}
+			$json['versions'][] = [
+				'version'   => (string)$version,
+				'providers' => $versionedProviders
+			];
+		}
+
+		return $json;
+	}
+}
\ No newline at end of file
diff --git a/src/Http/Response/Api/BoxDefinition.php b/src/Http/Response/Api/BoxDefinition.php
index 1cf9ab4..f24738e 100644
--- a/src/Http/Response/Api/BoxDefinition.php
+++ b/src/Http/Response/Api/BoxDefinition.php
@@ -7,9 +7,9 @@
 
 namespace Phagrancy\Http\Response\Api;
 
+use Phagrancy\Concern\GeneratesDefinition;
 use Phagrancy\Http\Response\Json;
 use Phagrancy\Model\Entity;
-use Psr\Http\Message\UriInterface;
 
 /**
  * Box JSON definition response
@@ -19,28 +19,15 @@
 class BoxDefinition
 	extends Json
 {
-	public function __construct(Entity\Box $box, UriInterface $uri)
+	use GeneratesDefinition;
+
+	/**
+	 * @var string The key name for the definition. API uses tag, non-API uses name
+	 */
+	protected $nameKey = 'tag';
+
+	protected function resolveUriPath(Entity\Box $box, $version, $provider)
 	{
-		$json = [
-			'tag'      => $box->path(),
-			'versions' => []
-		];
-		foreach ($box->versions() as $version => $providers) {
-			if (empty($providers)) {
-				continue;
-			}
-			$vpbs = [];
-			foreach ($providers as $provider) {
-				$vpbs[] = [
-					'name' => $provider,
-					'url'  => (string)$uri->withPath("/api/v1/box/{$box->path()}/version/{$version}/provider/{$provider}")
-				];
-			}
-			$json['versions'][] = [
-				'version'   => $version,
-				'providers' => $vpbs
-			];
-		}
-		parent::__construct($json);
+		return "/api/v1/box/{$box->path()}/version/{$version}/provider/{$provider}";
 	}
 }
\ No newline at end of file
diff --git a/src/Http/Response/BoxDefinition.php b/src/Http/Response/BoxDefinition.php
index 97bfb2f..6b9e3ad 100644
--- a/src/Http/Response/BoxDefinition.php
+++ b/src/Http/Response/BoxDefinition.php
@@ -7,8 +7,8 @@
 
 namespace Phagrancy\Http\Response;
 
+use Phagrancy\Concern\GeneratesDefinition;
 use Phagrancy\Model\Entity;
-use Psr\Http\Message\UriInterface;
 
 /**
  * Box JSON definition response
@@ -18,29 +18,15 @@
 class BoxDefinition
 	extends Json
 {
-	public function __construct(Entity\Box $box, UriInterface $uri)
-	{
-		$json = [
-			'name'      => (string)$box->path(),
-			'versions' => []
-		];
-		foreach ($box->versions() as $version => $providers) {
-			if (empty($providers)) {
-				continue;
-			}
-			$vpbs = [];
-			foreach ($providers as $provider) {
-				$vpbs[] = [
-					'name' => (string)$provider,
-					'url'  => (string)$uri->withPath("/{$box->path()}/{$version}/{$provider}")
-				];
-			}
-			$json['versions'][] = [
-				'version'   => strval($version),
-				'providers' => $vpbs
-			];
-		}
+	use GeneratesDefinition;
+
+	/**
+	 * @var string The key name for the definition. API uses tag, non-API uses name
+	 */
+	protected $nameKey = 'name';
 
-		parent::__construct($json);
+	protected function resolveUriPath(Entity\Box $box, $version, $provider)
+	{
+		return "/{$box->path()}/{$version}/{$provider}";
 	}
 }
diff --git a/src/Model/Input/ValidatesVersion.php b/src/Model/Input/ValidatesVersion.php
index 2a54a31..81fec27 100644
--- a/src/Model/Input/ValidatesVersion.php
+++ b/src/Model/Input/ValidatesVersion.php
@@ -26,9 +26,10 @@ trait ValidatesVersion
 	 */
 	public function validateVersion()
 	{
-		$error = "Version must be of the format x.y.z where x, y, and z are all integers, or follow SemVer 2.0.0";;
+		$error = "Version must be of the format x.y.z where x, y, and z are all integers";
 		return function ($value) use ($error) {
-			if (!preg_match('/^v?(0|[1-9]\d*)(?:\.(0|[1-9]\d*)){0,2}(?:(\.|-)[\da-z+_-]+)*$/i', $value)) {
+			// we support a subset of SemVer
+			if (!preg_match('/^(\d+)(?:\.(\d+)){0,2}(?:-[\da-z]+)*$/', $value)) {
 				return $error;
 			}
 
diff --git a/tests/unit/Model/Input/ValidatesVersionTest.php b/tests/unit/Model/Input/ValidatesVersionTest.php
index b511045..6346d7d 100644
--- a/tests/unit/Model/Input/ValidatesVersionTest.php
+++ b/tests/unit/Model/Input/ValidatesVersionTest.php
@@ -23,10 +23,11 @@ public function provideGoodVersions()
 			['20180609'],
 			['20180609.13425'],
 			['1.2.3'],
-			['1.alpha_a'],
-			['1.2.3.alpha'],
-			['1.2.3.0+b'],
-			['1.2.3-alpha.10.beta.0+build.unicorn.rainbow'],
+			['1.2.3-alpha'],
+			['1.2.3-alpha-build'],
+			['1-beta'],
+			['1.2-charlie'],
+			['0.1']
 		];
 	}
 
@@ -34,6 +35,12 @@ public function provideBadVersions()
 	{
 		return [
 			['1.-1'],
+			['v5'],
+			['1.alpha_a'],
+			['1.2.3.alpha'],
+			['1.2.3.0+b'],
+			['1.2.3-alpha build'],
+			['1.2.3-alpha.10.beta.0+build.unicorn.rainbow'],
 		];
 	}