diff --git a/dbms/src/IO/PeekableReadBuffer.cpp b/dbms/src/IO/PeekableReadBuffer.cpp
index 82ac1f444b4..eff935a9de5 100644
--- a/dbms/src/IO/PeekableReadBuffer.cpp
+++ b/dbms/src/IO/PeekableReadBuffer.cpp
@@ -3,12 +3,6 @@
 namespace DB
 {
 
-namespace ErrorCodes
-{
-    extern const int LOGICAL_ERROR;
-    extern const int MEMORY_LIMIT_EXCEEDED;
-}
-
 PeekableReadBuffer::PeekableReadBuffer(ReadBuffer & sub_buf_, size_t start_size_ /*= DBMS_DEFAULT_BUFFER_SIZE*/,
                                                               size_t unread_limit_ /* = default_limit*/)
         : BufferWithOwnMemory(start_size_), sub_buf(sub_buf_), unread_limit(unread_limit_)
diff --git a/dbms/src/IO/PeekableReadBuffer.h b/dbms/src/IO/PeekableReadBuffer.h
index bfc1dac5483..f632b4a4b20 100644
--- a/dbms/src/IO/PeekableReadBuffer.h
+++ b/dbms/src/IO/PeekableReadBuffer.h
@@ -5,6 +5,12 @@
 namespace DB
 {
 
+namespace ErrorCodes
+{
+    extern const int LOGICAL_ERROR;
+    extern const int MEMORY_LIMIT_EXCEEDED;
+}
+
 /// Also allows to set checkpoint at some position in stream and come back to this position later.
 /// When next() is called, saves data between checkpoint and current position to own memory and loads next data to sub-buffer
 /// Sub-buffer should not be accessed directly during the lifetime of peekable buffer.