diff --git a/dbms/src/Common/CurrentThread.cpp b/dbms/src/Common/CurrentThread.cpp
index 446772f218d..ca39bec414c 100644
--- a/dbms/src/Common/CurrentThread.cpp
+++ b/dbms/src/Common/CurrentThread.cpp
@@ -51,12 +51,6 @@ MemoryTracker * CurrentThread::getMemoryTracker()
     return &current_thread->memory_tracker;
 }
 
-Int64 & CurrentThread::getUntrackedMemory()
-{
-    /// It assumes that (current_thread != nullptr) is already checked with getMemoryTracker()
-    return current_thread->untracked_memory;
-}
-
 void CurrentThread::updateProgressIn(const Progress & value)
 {
     if (unlikely(!current_thread))
diff --git a/dbms/src/Common/CurrentThread.h b/dbms/src/Common/CurrentThread.h
index 01e46fbeadc..1e0140c6330 100644
--- a/dbms/src/Common/CurrentThread.h
+++ b/dbms/src/Common/CurrentThread.h
@@ -52,7 +52,12 @@ public:
 
     static ProfileEvents::Counters & getProfileEvents();
     static MemoryTracker * getMemoryTracker();
-    static Int64 & getUntrackedMemory();
+
+    static inline Int64 & getUntrackedMemory()
+    {
+        /// It assumes that (current_thread != nullptr) is already checked with getMemoryTracker()
+        return current_thread->untracked_memory;
+    }
 
     /// Update read and write rows (bytes) statistics (used in system.query_thread_log)
     static void updateProgressIn(const Progress & value);