diff --git a/src/resolver.ts b/src/resolver.ts
index 77f1928..f60aedd 100644
--- a/src/resolver.ts
+++ b/src/resolver.ts
@@ -95,7 +95,7 @@ export const resolver = <T, Chain, R>(wretch: T & Wretch<T, Chain, R>) => {
     })
   }
   // Enforces the proper promise type when a body parsing method is called.
-  type BodyParser = <Type>(funName: string | null) => <Result = void>(cb?: (type: Type) => Result) => Promise<Awaited<Result>>
+  type BodyParser = <Type>(funName: "json" | "blob" | "formData" | "arrayBuffer" | "text" | null) => <Result = void>(cb?: (type: Type) => Result) => Promise<Awaited<Result>>
   const bodyParser: BodyParser = funName => cb => funName ?
     // If a callback is provided, then callback with the body result otherwise return the parsed body itself.
     catchersWrapper(throwingPromise.then(_ => _ && _[funName]()).then(_ => cb ? cb(_) : _)) :
@@ -127,7 +127,7 @@ export const resolver = <T, Chain, R>(wretch: T & Wretch<T, Chain, R>) => {
 
   const enhancedResponseChain: R extends undefined ? Chain & WretchResponseChain<T, Chain, undefined> : R = addons.reduce((chain, addon) => ({
     ...chain,
-    ...(addon.resolver as any)
+    ...(typeof addon.resolver === "function" ? (addon.resolver as (_: WretchResponseChain<T, Chain, R>) => any)(chain) : addon.resolver)
   }), responseChain)
 
   return resolvers.reduce((chain, r) => r(chain, wretch), enhancedResponseChain)
diff --git a/src/types.ts b/src/types.ts
index 61061b9..e69d2de 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -786,6 +786,6 @@ export type FetchLike = (url: string, opts: WretchOptions) => Promise<WretchResp
 export type WretchAddon<W extends unknown, R extends unknown = unknown> = {
   beforeRequest?<T, C, R>(wretch: T & Wretch<T, C, R>, options: WretchOptions, state: Record<any, any>): T & Wretch<T, C, R>,
   wretch?: W,
-  resolver?: R
+  resolver?: R | (<T, C>(_: C & WretchResponseChain<T, C, R>) => R)
 }
 
diff --git a/tsconfig.json b/tsconfig.json
index ebc134c..8942c9c 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -17,7 +17,6 @@
     "isolatedModules": true
   },
   "include": [
-    "src/**/*",
-    "test.ts"
+    "src/**/*"
   ]
 }
\ No newline at end of file