diff --git a/programs/disks/CommandSwitchDisk.cpp b/programs/disks/CommandSwitchDisk.cpp
index e59a1fc8e87..0eb7ced7abf 100644
--- a/programs/disks/CommandSwitchDisk.cpp
+++ b/programs/disks/CommandSwitchDisk.cpp
@@ -8,6 +8,11 @@
 namespace DB
 {
 
+namespace ErrorCodes
+{
+extern const int BAD_ARGUMENTS;
+};
+
 class CommandSwitchDisk final : public ICommand
 {
 public:
diff --git a/programs/disks/DisksApp.cpp b/programs/disks/DisksApp.cpp
index 10eb3f986b9..dd3c60c7630 100644
--- a/programs/disks/DisksApp.cpp
+++ b/programs/disks/DisksApp.cpp
@@ -24,6 +24,13 @@
 namespace DB
 {
 
+namespace ErrorCodes
+{
+extern const int BAD_ARGUMENTS;
+extern const int LOGICAL_ERROR;
+};
+
+
 CommandPtr DisksApp::getCommandByName(String command) const
 {
     auto it = aliases.find(command);
diff --git a/programs/disks/DisksApp.h b/programs/disks/DisksApp.h
index 7c9150cd1ce..a0ce98b51d0 100644
--- a/programs/disks/DisksApp.h
+++ b/programs/disks/DisksApp.h
@@ -15,12 +15,6 @@
 namespace DB
 {
 
-namespace ErrorCodes
-{
-extern const int BAD_ARGUMENTS;
-extern const int LOGICAL_ERROR;
-};
-
 using ProgramOptionsDescription = boost::program_options::options_description;
 using CommandLineOptions = boost::program_options::variables_map;
 
diff --git a/programs/disks/ICommand_fwd.h b/programs/disks/ICommand_fwd.h
index f45b6c8d17c..84310b4a18d 100644
--- a/programs/disks/ICommand_fwd.h
+++ b/programs/disks/ICommand_fwd.h
@@ -1,6 +1,6 @@
-#include <memory>
-#include <string>
+#pragma once
 
+#include <memory>
 
 namespace DB
 {