diff --git a/ChangeLog b/ChangeLog
index 8c75a32f4c2..acc0d990eb3 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -6687,4 +6687,5 @@
 	* configs/*/defconfig:  If CONFIG_NSH_LIBRARY=y then set CONFIG_NSH_READLINE=y
 	  otherwise the CLE will be selected by default the next time that
 	  make menuconfig is used (2014-2-28).
+	* include/cxx/cstdbool:  Ignore _Bool8 if CONFIG_C99_BOOL8=y. (2014-2-28).
  
diff --git a/include/cxx/cstdbool b/include/cxx/cstdbool
index 192fde490b3..d21a13b35cf 100644
--- a/include/cxx/cstdbool
+++ b/include/cxx/cstdbool
@@ -50,9 +50,11 @@
 // Namespace
 //***************************************************************************
 
+#ifndef CONFIG_C99_BOOL8
 namespace std
 {
   using ::_Bool8;
 }
+#endif
 
 #endif // __INCLUDE_CXX_CSTDBOOL