Index: /trunk/Config.kmk
===================================================================
--- /trunk/Config.kmk	(revision 85336)
+++ /trunk/Config.kmk	(revision 85337)
@@ -2945,5 +2945,5 @@
 	$(QUIET)$(APPEND) '$@' 'VBOX_GCC_Wno-nested-anon-types ?= $(call VBOX_GCC_CHECK_CC,-Wno-nested-anon-types,)'
 	$(QUIET)$(APPEND) '$@' 'VBOX_GCC_Wno-gnu-anonymous-struct ?= $(call VBOX_GCC_CHECK_CXX,-Wno-gnu-anonymous-struct,)'
-# CLang 11.
+# Clang 11.
 	$(QUIET)$(APPEND) '$@' 'VBOX_GCC_Wno-c++17-compat-mangling ?= $(call VBOX_GCC_CHECK_CXX,-Wno-c++17-compat-mangling,)'
 	$(QUIET)$(APPEND) '$@' 'VBOX_GCC_Wno-nullability-extension ?= $(call VBOX_GCC_CHECK_CXX,-Wno-nullability-extension,)'
@@ -2951,4 +2951,5 @@
 	$(QUIET)$(APPEND) '$@' 'VBOX_GCC_Wno-import-preprocessor-directive-pedantic ?= $(call VBOX_GCC_CHECK_CXX,-Wno-import-preprocessor-directive-pedantic,)'
 	$(QUIET)$(APPEND) '$@' 'VBOX_GCC_Wno-undefined-var-template ?= $(call VBOX_GCC_CHECK_CXX,-Wno-undefined-var-template,)'
+	$(QUIET)$(APPEND) '$@' 'VBOX_GCC_Wno-c11-extensions ?= $(call VBOX_GCC_CHECK_CXX,-Wno-c11-extensions,)'
 ifeq ($(KBUILD_TARGET),solaris)
 	$(QUIET)$(APPEND) '$@' 'VBOX_GCC_msave-args            ?= $(call VBOX_GCC_CHECK_CXX,-msave-args,)'
@@ -4904,5 +4905,5 @@
 	-Werror=non-modular-include-in-framework-module \
 	$(VBOX_GCC_Wno-nullability-extension) $(VBOX_GCC_Wno-gnu-statement-expression) \
-       $(VBOX_GCC_Wno-import-preprocessor-directive-pedantic) \
+       $(VBOX_GCC_Wno-import-preprocessor-directive-pedantic) $(VBOX_GCC_Wno-c11-extensions) \
 	$(VBOX_GCC_R0_OPT) $(VBOX_GCC_R0_FP) -fasm-blocks -fno-strict-aliasing -stdlib=libc++
 #  if1of ($(VBOX_GCC_TOOL), CLANGXXMACHO) ## @todo check if we can safely use $(VBOX_GCC_std) @bugref{9790}, good for noexcept.
@@ -4926,5 +4927,5 @@
 	-fno-exceptions -msoft-float -fapple-kext -fno-rtti  \
 	-fmodules -fmodules-prune-interval=86400 -fmodules-prune-after=345600 -Wnon-modular-include-in-framework-module \
-	-Werror=non-modular-include-in-framework-module \
+	-Werror=non-modular-include-in-framework-module $(VBOX_GCC_Wno-c11-extensions) \
 	$(VBOX_GCC_R0_OPT) $(VBOX_GCC_R0_FP) -fasm-blocks -fno-strict-aliasing
 TEMPLATE_VBOXR0DRV_CFLAGS.amd64        = -m64 -mno-red-zone