diff --git a/[refs] b/[refs]
index 0225d6d8b1c1..c905d18a5cc5 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: ce454d4d7278b815dcee957653ce388146484f5f
+refs/heads/master: 3c521e06fad4b4b7fe4811fb8363d12cf49f40a2
diff --git a/trunk/Makefile b/trunk/Makefile
index 5185c917077b..423397f03921 100644
--- a/trunk/Makefile
+++ b/trunk/Makefile
@@ -203,7 +203,7 @@ CONFIG_SHELL := $(shell if [ -x "$$BASH" ]; then echo $$BASH; \
 
 HOSTCC  	= gcc
 HOSTCXX  	= g++
-HOSTCFLAGS	= -Wall -Wstrict-prototypes -O2 -fomit-frame-pointer
+HOSTCFLAGS	= -Wall -Wundef -Wstrict-prototypes -O2 -fomit-frame-pointer
 HOSTCXXFLAGS	= -O2
 
 # 	Decide whether to build built-in, modular, or both.
@@ -348,7 +348,7 @@ LINUXINCLUDE    := -Iinclude \
 
 CPPFLAGS        := -D__KERNEL__ $(LINUXINCLUDE)
 
-CFLAGS 		:= -Wall -Wstrict-prototypes -Wno-trigraphs \
+CFLAGS 		:= -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
 	  	   -fno-strict-aliasing -fno-common \
 		   -ffreestanding
 AFLAGS		:= -D__ASSEMBLY__