diff --git a/src/util/stopwatch.h b/src/util/stopwatch.h
index b1f6bba03..7a9066030 100644
--- a/src/util/stopwatch.h
+++ b/src/util/stopwatch.h
@@ -43,6 +43,8 @@ public:
     }
 
     ~stopwatch() {};
+    
+    void add (const stopwatch &s) {/* TODO */}
 
     void reset() { m_elapsed.QuadPart = 0; }
     
@@ -90,6 +92,8 @@ public:
 
     ~stopwatch() {}
     
+    void add (const stopwatch &s) {m_time += s.m_time;}
+    
     void reset() {
         m_time = 0ull;
     }
@@ -141,6 +145,8 @@ public:
 
     ~stopwatch() {}
     
+    void add (const stopwatch &s) {m_time += s.m_time;}
+    
     void reset() {
         m_time = 0ull;
     }