diff --git a/src/Core/QualifiedTableName.cpp b/src/Core/QualifiedTableName.cpp
index 661cc4227b1..b32764f93a0 100644
--- a/src/Core/QualifiedTableName.cpp
+++ b/src/Core/QualifiedTableName.cpp
@@ -6,6 +6,11 @@
 namespace DB
 {
 
+namespace ErrorCodes
+{
+extern const int SYNTAX_ERROR;
+}
+
 UInt64 QualifiedTableName::hash() const
 {
     SipHash hash_state;
diff --git a/src/Core/QualifiedTableName.h b/src/Core/QualifiedTableName.h
index 79c101b915e..86a903be406 100644
--- a/src/Core/QualifiedTableName.h
+++ b/src/Core/QualifiedTableName.h
@@ -9,11 +9,6 @@
 namespace DB
 {
 
-namespace ErrorCodes
-{
-extern const int SYNTAX_ERROR;
-}
-
 //TODO replace with StorageID
 struct QualifiedTableName
 {