diff --git a/.eslintrc b/.eslintrc
index 7adb806a..14fb0748 100644
--- a/.eslintrc
+++ b/.eslintrc
@@ -76,6 +76,8 @@
 			"parser": "@typescript-eslint/parser",
 			"plugins": ["@typescript-eslint"],
 			"rules": {
+				"no-shadow": "off",
+				"@typescript-eslint/no-shadow": "warn",
 				"node/no-unsupported-features/es-syntax": "off"
 			}
 		},
diff --git a/index.d.ts b/index.d.ts
index 7b3307f7..1fd1eac9 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -21,7 +21,9 @@ export type RegistryContentType =
 /**
  * Container for all registered metrics
  */
-export class Registry<RegistryContentType = PrometheusContentType> {
+export class Registry<
+	BoundRegistryContentType extends RegistryContentType = PrometheusContentType,
+> {
 	/**
 	 * Get string representation for all metrics
 	 */
@@ -81,14 +83,14 @@ export class Registry<RegistryContentType = PrometheusContentType> {
 	/**
 	 * Gets the Content-Type of the metrics for use in the response headers.
 	 */
-	readonly contentType: RegistryContentType;
+	readonly contentType: BoundRegistryContentType;
 
 	/**
 	 * Set the content type of a registry. Used to change between Prometheus and
 	 * OpenMetrics versions.
 	 * @param contentType The type of the registry
 	 */
-	setContentType(contentType: RegistryContentType): void;
+	setContentType(contentType: BoundRegistryContentType): void;
 
 	/**
 	 * Merge registers