diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 6295c2e7579..3518241e598 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -30,6 +30,7 @@ ldflags-y  :=
 
 subdir-asflags-y :=
 subdir-ccflags-y :=
+subdir-cxxflags-y :=
 
 # Read auto.conf if it exists, otherwise ignore
 -include include/config/auto.conf
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index b907af8ab34..29aa73d5c8a 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -10,6 +10,7 @@ ldflags-y  += $(EXTRA_LDFLAGS)
 # flags that take effect in sub directories
 export KBUILD_SUBDIR_ASFLAGS := $(KBUILD_SUBDIR_ASFLAGS) $(subdir-asflags-y)
 export KBUILD_SUBDIR_CCFLAGS := $(KBUILD_SUBDIR_CCFLAGS) $(subdir-ccflags-y)
+export KBUILD_SUBDIR_CXXFLAGS := $(KBUILD_SUBDIR_CXXFLAGS) $(subdir-cxxflags-y)
 
 # Figure out what we need to build from the various variables
 # ===========================================================================