diff --git a/bitbake/lib/bb/asyncrpc/serv.py b/bitbake/lib/bb/asyncrpc/serv.py
index 5fed1730df..f0be9a6cdb 100644
--- a/bitbake/lib/bb/asyncrpc/serv.py
+++ b/bitbake/lib/bb/asyncrpc/serv.py
@@ -322,7 +322,7 @@ class AsyncServer(object):
         self.loop = asyncio.new_event_loop()
         asyncio.set_event_loop(self.loop)
 
-    def serve_as_process(self, *, prefunc=None, args=()):
+    def serve_as_process(self, *, prefunc=None, args=(), log_level=None):
         """
         Serve requests in a child process
         """
@@ -351,6 +351,9 @@ class AsyncServer(object):
             if prefunc is not None:
                 prefunc(self, *args)
 
+            if log_level is not None:
+                self.logger.setLevel(log_level)
+
             self._serve_forever(tasks)
 
             if sys.version_info >= (3, 6):
diff --git a/bitbake/lib/bb/cooker.py b/bitbake/lib/bb/cooker.py
index 9a3e32ac1b..4bf1809bc0 100644
--- a/bitbake/lib/bb/cooker.py
+++ b/bitbake/lib/bb/cooker.py
@@ -345,7 +345,7 @@ class BBCooker:
                     sync=False,
                     upstream=upstream,
                 )
-                self.hashserv.serve_as_process()
+                self.hashserv.serve_as_process(log_level=logging.WARNING)
             for mc in self.databuilder.mcdata:
                 self.databuilder.mcorigdata[mc].setVar("BB_HASHSERVE", self.hashservaddr)
                 self.databuilder.mcdata[mc].setVar("BB_HASHSERVE", self.hashservaddr)
diff --git a/bitbake/lib/prserv/serv.py b/bitbake/lib/prserv/serv.py
index 6168eb183d..62d3b5a01c 100644
--- a/bitbake/lib/prserv/serv.py
+++ b/bitbake/lib/prserv/serv.py
@@ -130,7 +130,7 @@ class PRServSingleton(object):
     def start(self):
         self.prserv = PRServer(self.dbfile)
         self.prserv.start_tcp_server(socket.gethostbyname(self.host), self.port)
-        self.process = self.prserv.serve_as_process()
+        self.process = self.prserv.serve_as_process(log_level=logging.WARNING)
 
         if not self.prserv.address:
             raise PRServiceConfigError