diff --git a/dbms/src/Common/getNumberOfPhysicalCPUCores.cpp b/dbms/src/Common/getNumberOfPhysicalCPUCores.cpp
index 927aa41e2c8..8611e68f5c3 100644
--- a/dbms/src/Common/getNumberOfPhysicalCPUCores.cpp
+++ b/dbms/src/Common/getNumberOfPhysicalCPUCores.cpp
@@ -5,10 +5,7 @@
 	#include <cpuid/libcpuid.h>
 	#include <DB/Common/Exception.h>
 
-	namespace ErrorCodes
-	{
-		extern const int CPUID_ERROR;
-	}
+	namespace DB { namespace ErrorCodes { extern const int CPUID_ERROR; }}
 
 #elif defined(__aarch64__)