diff --git a/test/types/instance.test-d.ts b/test/types/instance.test-d.ts
index ba4d5ce927..520de16d40 100644
--- a/test/types/instance.test-d.ts
+++ b/test/types/instance.test-d.ts
@@ -16,6 +16,7 @@ import { DefaultRoute } from '../../types/route'
 import { FastifySchemaControllerOptions, FastifySchemaCompiler, FastifySerializerCompiler } from '../../types/schema'
 import { AddressInfo } from 'net'
 import { Bindings, ChildLoggerOptions } from '../../types/logger'
+import pino from 'pino'
 
 const server = fastify()
 
@@ -312,6 +313,8 @@ function childLoggerFactory (this: FastifyInstance, logger: FastifyBaseLogger, b
 server.setChildLoggerFactory(childLoggerFactory)
 server.setChildLoggerFactory(server.childLoggerFactory)
 
+expectAssignable<FastifyInstance>(fastify({ logger: pino() as FastifyBaseLogger }))
+
 type InitialConfig = Readonly<{
   connectionTimeout?: number,
   keepAliveTimeout?: number,
diff --git a/types/instance.d.ts b/types/instance.d.ts
index da3971e933..859c5a7c08 100644
--- a/types/instance.d.ts
+++ b/types/instance.d.ts
@@ -488,7 +488,7 @@ export interface FastifyInstance<
    * which allows for modifying or adding child logger bindings and logger options, or
    * returning a completely custom child logger implementation.
    */
-  childLoggerFactory: FastifyChildLoggerFactory<RawServer, RawRequest, RawReply, Logger, TypeProvider>;
+  childLoggerFactory: FastifyChildLoggerFactory<RawServer, RawRequest, RawReply, FastifyBaseLogger, TypeProvider>;
 
   /**
    * Hook function that is called when creating a child logger instance for each request