diff --git a/src/Access/Authentication.cpp b/src/Access/Authentication.cpp
index cb67924475b..be11bf7ba27 100644
--- a/src/Access/Authentication.cpp
+++ b/src/Access/Authentication.cpp
@@ -13,10 +13,6 @@
 
 namespace DB
 {
-namespace ErrorCodes
-{
-    extern const int LOGICAL_ERROR;
-}
 
 namespace
 {