diff --git a/lib/fluent/plugin_helper/server.rb b/lib/fluent/plugin_helper/server.rb
index 97ee96d97e..69671ae47b 100644
--- a/lib/fluent/plugin_helper/server.rb
+++ b/lib/fluent/plugin_helper/server.rb
@@ -377,7 +377,7 @@ def server_create_udp_socket(shared, bind, port)
       end
 
       # Use string "?" for port, not integer or nil. "?" is clear than -1 or nil in the log.
-      PEERADDR_FAILED = ["?", "?", "name resolusion failed", "?"]
+      PEERADDR_FAILED = ["?", "?", "name resolution failed", "?"]
 
       class CallbackSocket
         def initialize(server_type, sock, enabled_events = [], close_socket: true)