diff --git a/src/base/disable_copying.h b/src/base/disable_copying.h
index 1a18757d3..b523097ac 100644
--- a/src/base/disable_copying.h
+++ b/src/base/disable_copying.h
@@ -8,7 +8,8 @@
 #define BASE_DISABLE_COPYING_H_INCLUDED
 
 #define DISABLE_COPYING(ClassName)		\
-  ClassName(const ClassName&);			\
-  ClassName& operator=(const ClassName&);
+  private:					\
+    ClassName(const ClassName&);		\
+    ClassName& operator=(const ClassName&);
 
 #endif