diff --git a/composer.json b/composer.json
index 9a2d6d7..e278b32 100644
--- a/composer.json
+++ b/composer.json
@@ -4,7 +4,7 @@
     "type": "library",
     "license": "OSL-3.0",
     "require": {
-        "php": "~7.4.0||~8.1.0",
+        "php": "~8.1.0||~8.2.0",
         "mustache/mustache": "^2.12",
         "xantios/mimey": "^2.2",
         "symfony/yaml": "^2.3 || ^3.3 || ^4.0 || ^5.0",
diff --git a/src/Controller.php b/src/Controller.php
index 6873f03..8e42299 100644
--- a/src/Controller.php
+++ b/src/Controller.php
@@ -43,7 +43,7 @@ public function __construct(
 
         foreach (self::STANDARD_FIELDS as $key) {
             if (!$this->definition->has($key)) {
-                throw new \RuntimeException("Definition YAML is missing required key: ${key}");
+                throw new \RuntimeException("Definition YAML is missing required key: {$key}");
             }
         }
 
diff --git a/src/Definition.php b/src/Definition.php
index 8fa6010..878834a 100644
--- a/src/Definition.php
+++ b/src/Definition.php
@@ -44,7 +44,7 @@ public static function fromYamlFile(string $filePath): self
         $data = Yaml::parseFile($filePath);
 
         if (!\is_array($data)) {
-            throw new \InvalidArgumentException("File ${filePath} could not be parsed as YAML.");
+            throw new \InvalidArgumentException("File {$filePath} could not be parsed as YAML.");
         }
 
         $instance = new static($data);
diff --git a/src/Resolver/Url.php b/src/Resolver/Url.php
index d0c525f..05c112d 100644
--- a/src/Resolver/Url.php
+++ b/src/Resolver/Url.php
@@ -78,7 +78,7 @@ public function resolve($definition)
             $currentPathname = $uri->getPath();
             if ($pathname[0] !== '/') {
                 if ($currentPathname === null) {
-                    $pathname = "/${pathname}";
+                    $pathname = "/{$pathname}";
                 } elseif ($currentPathname[\strlen($currentPathname) - 1] === '/') {
                     $pathname = $currentPathname . $pathname;
                 } else {
diff --git a/src/Template/TemplateFactory.php b/src/Template/TemplateFactory.php
index 6680eb2..6026863 100644
--- a/src/Template/TemplateFactory.php
+++ b/src/Template/TemplateFactory.php
@@ -37,6 +37,6 @@ public static function get(string $basePath, ?string $engine): TemplateInterface
             }
         }
 
-        throw new \InvalidArgumentException("${engine} could not be found or does not implement TemplateInterface");
+        throw new \InvalidArgumentException("{$engine} could not be found or does not implement TemplateInterface");
     }
 }