Index: kernel/Makefile.build
===================================================================
--- kernel/Makefile.build	(revision 101d9f4939436823013482f00c5df3706b846bf7)
+++ kernel/Makefile.build	(revision 39e8406404efea86e341847c0720d5d65bed7959)
@@ -56,5 +56,6 @@
 	-finput-charset=UTF-8 -ffreestanding -fno-builtin -nostdlib -nostdinc \
 	-Wall -Wextra -Wno-unused-parameter -Wmissing-prototypes \
-	-Werror-implicit-function-declaration -Werror -pipe
+	-Werror-implicit-function-declaration -Wwrite-strings \
+	-Werror -pipe
 
 ICC_CFLAGS = -I$(INCLUDES) -O$(OPTIMIZATION) -imacros ../config.h \
@@ -69,6 +70,7 @@
 	-fexec-charset=UTF-8 -fwide-exec-charset=UTF-32$(ENDIANESS) \
 	-finput-charset=UTF-8 -ffreestanding -fno-builtin -nostdlib -nostdinc \
-	-Wall -Wextra -Wno-unused-parameter -Wmissing-prototypes -pipe \
-	-arch $(CLANG_ARCH)
+	-Wall -Wextra -Wno-unused-parameter -Wmissing-prototypes \
+	-Werror-implicit-function-declaration -Wwrite-strings \
+	-pipe -arch $(CLANG_ARCH)
 
 LFLAGS = -M