--- Config.mk
+++ Config.mk
@@ -18,7 +18,7 @@
 
 # Tools to run on system hosting the build
 HOSTCC     = gcc
-HOSTCFLAGS = -Wall -Werror -Wstrict-prototypes -O2 -fomit-frame-pointer
+HOSTCFLAGS = -Wall -Wstrict-prototypes -O2 -fomit-frame-pointer
 
 DISTDIR     ?= $(XEN_ROOT)/dist
 DESTDIR     ?= /
--- extras/mini-os/minios.mk
+++ extras/mini-os/minios.mk
@@ -6,7 +6,7 @@
 
 # Define some default flags.
 # NB. '-Wcast-qual' is nasty, so I omitted it.
-DEF_CFLAGS := -fno-builtin -Wall -Werror -Wredundant-decls -Wno-format
+DEF_CFLAGS := -fno-builtin -Wall -Wredundant-decls -Wno-format
 DEF_CFLAGS += -Wstrict-prototypes -Wnested-externs -Wpointer-arith -Winline
 DEF_CFLAGS += -D__XEN_INTERFACE_VERSION__=$(XEN_INTERFACE_VERSION)
 
--- tools/blktap/drivers/Makefile
+++ tools/blktap/drivers/Makefile
@@ -8,7 +8,6 @@
 INST_DIR     = /usr/sbin
 LIBAIO_DIR   = ../../libaio/src
 
-CFLAGS   += -Werror
 CFLAGS   += -Wno-unused
 CFLAGS   += -fno-strict-aliasing
 CFLAGS   += -I $(XEN_LIBXC) -I $(LIBAIO_DIR)
--- tools/blktap/lib/Makefile
+++ tools/blktap/lib/Makefile
@@ -14,7 +14,6 @@
 SRCS     :=
 SRCS     += xenbus.c blkif.c xs_api.c
 
-CFLAGS   += -Werror
 CFLAGS   += -Wno-unused
 CFLAGS   += -fno-strict-aliasing -fPIC
 # get asprintf():
--- tools/console/Makefile
+++ tools/console/Makefile
@@ -5,8 +5,6 @@
 DAEMON_INSTALL_DIR = /usr/sbin
 CLIENT_INSTALL_DIR = /usr/$(LIBDIR)/xen/bin
 
-CFLAGS  += -Werror
-
 CFLAGS  += -I $(XEN_LIBXC)
 CFLAGS  += -I $(XEN_XENSTORE)
 
--- tools/ioemu/Makefile.target
+++ tools/ioemu/Makefile.target
@@ -581,5 +581,5 @@
 ifeq (1, 0)
 audio.o sdlaudio.o dsoundaudio.o ossaudio.o wavaudio.o noaudio.o \
 fmodaudio.o alsaaudio.o mixeng.o sb16.o es1370.o gus.o adlib.o: \
-CFLAGS := $(CFLAGS) -Wall -Werror -W -Wsign-compare
+CFLAGS := $(CFLAGS) -Wall -W -Wsign-compare
 endif
--- tools/libaio/harness/Makefile
+++ tools/libaio/harness/Makefile
@@ -4,7 +4,7 @@
 HARNESS_SRCS:=main.c
 # io_queue.c
 
-CFLAGS=-Wall -Werror -g -O -laio
+CFLAGS=-Wall -g -O -laio
 #-lpthread -lrt
 
 all: $(PROGS)
--- tools/libfsimage/common/Makefile
+++ tools/libfsimage/common/Makefile
@@ -4,7 +4,7 @@
 MAJOR = 1.0
 MINOR = 0
 
-CFLAGS += -Werror -Wp,-MD,.$(@F).d
+CFLAGS += -Wp,-MD,.$(@F).d
 DEPS = .*.d
 
 LDFLAGS-$(CONFIG_SunOS) = -Wl,-M -Wl,mapfile-SunOS
--- tools/libfsimage/Rules.mk
+++ tools/libfsimage/Rules.mk
@@ -2,7 +2,7 @@
 
 DEPS = .*.d
 
-CFLAGS += -I$(XEN_ROOT)/tools/libfsimage/common/ -Werror -Wp,-MD,.$(@F).d
+CFLAGS += -I$(XEN_ROOT)/tools/libfsimage/common/ -Wp,-MD,.$(@F).d
 LDFLAGS += -L../common/
 
 PIC_OBJS := $(patsubst %.c,%.opic,$(LIB_SRCS-y))
--- tools/libxc/Makefile
+++ tools/libxc/Makefile
@@ -56,7 +56,7 @@
 
 -include $(XEN_TARGET_ARCH)/Makefile
 
-CFLAGS   += -Werror -Wmissing-prototypes
+CFLAGS   += -Wmissing-prototypes
 CFLAGS   += -fno-strict-aliasing
 CFLAGS   += $(INCLUDES) -I. -I../xenstore
 
--- tools/libxen/Makefile
+++ tools/libxen/Makefile
@@ -24,7 +24,7 @@
 CFLAGS = -Iinclude                     \
          $(shell xml2-config --cflags) \
          $(shell curl-config --cflags) \
-         -W -Wall -Wmissing-prototypes -Werror -std=c99 -O2 -fPIC
+         -W -Wall -Wmissing-prototypes -std=c99 -O2 -fPIC
 
 LDFLAGS = $(shell xml2-config --libs) \
           $(shell curl-config --libs)
--- tools/libxen/Makefile.dist
+++ tools/libxen/Makefile.dist
@@ -22,7 +22,7 @@
 CFLAGS = -Iinclude                     \
          $(shell xml2-config --cflags) \
          $(shell curl-config --cflags) \
-         -W -Wall -Wmissing-prototypes -Werror -std=c99 -O2 -fPIC
+         -W -Wall -Wmissing-prototypes -std=c99 -O2 -fPIC
 
 LDFLAGS = $(shell xml2-config --libs) \
           $(shell curl-config --libs)
--- tools/misc/lomount/Makefile
+++ tools/misc/lomount/Makefile
@@ -1,8 +1,6 @@
 XEN_ROOT=../../..
 include $(XEN_ROOT)/tools/Rules.mk
 
-CFLAGS  += -Werror
-
 HDRS     = $(wildcard *.h)
 OBJS     = $(patsubst %.c,%.o,$(wildcard *.c))
 
--- tools/misc/Makefile
+++ tools/misc/Makefile
@@ -1,8 +1,6 @@
 XEN_ROOT=../..
 include $(XEN_ROOT)/tools/Rules.mk
 
-CFLAGS   += -Werror
-
 INCLUDES += -I $(XEN_XC)
 INCLUDES += -I $(XEN_LIBXC)
 CFLAGS   += $(INCLUDES)
--- tools/pygrub/setup.py
+++ tools/pygrub/setup.py
@@ -3,7 +3,7 @@
 import os
 import sys
 
-extra_compile_args  = [ "-fno-strict-aliasing", "-Werror" ]
+extra_compile_args  = [ "-fno-strict-aliasing" ]
 
 XEN_ROOT = "../.."
 
--- tools/python/setup.py
+++ tools/python/setup.py
@@ -4,7 +4,7 @@
 
 XEN_ROOT = "../.."
 
-extra_compile_args  = [ "-fno-strict-aliasing", "-Werror" ]
+extra_compile_args  = [ "-fno-strict-aliasing" ]
 
 include_dirs = [ XEN_ROOT + "/tools/libxc",
                  XEN_ROOT + "/tools/xenstore",
--- tools/security/Makefile
+++ tools/security/Makefile
@@ -1,7 +1,6 @@
 XEN_ROOT = ../..
 include $(XEN_ROOT)/tools/Rules.mk
 
-CFLAGS   += -Werror
 CFLAGS   += -fno-strict-aliasing
 CFLAGS   += -I. -I $(XEN_LIBXC)
 
--- tools/vnet/libxutil/Makefile
+++ tools/vnet/libxutil/Makefile
@@ -24,7 +24,7 @@
 LIB_OBJS := $(LIB_SRCS:.c=.o)
 PIC_OBJS := $(LIB_SRCS:.c=.opic)
 
-CFLAGS   += -Werror -fno-strict-aliasing
+CFLAGS   += -fno-strict-aliasing
 CFLAGS   += -O3
 #CFLAGS   += -g
 
--- tools/vtpm/Rules.mk
+++ tools/vtpm/Rules.mk
@@ -9,7 +9,7 @@
 TOOLS_INSTALL_DIR = $(DESTDIR)/usr/bin
 
 # General compiler flags
-CFLAGS   = -Werror -g3 -I.
+CFLAGS   = -g3 -I.
 
 # For generating dependencies
 CFLAGS	+= -Wp,-MD,.$(@F).d
--- tools/vtpm_manager/Rules.mk
+++ tools/vtpm_manager/Rules.mk
@@ -9,7 +9,7 @@
 TOOLS_INSTALL_DIR = $(DESTDIR)/usr/bin
 
 # General compiler flags
-CFLAGS	= -Werror -g3 -I.
+CFLAGS	= -g3 -I.
 
 # For generating dependencies
 CFLAGS	+= -Wp,-MD,.$(@F).d
--- tools/xcutils/Makefile
+++ tools/xcutils/Makefile
@@ -15,7 +15,7 @@
 
 INCLUDES += -I $(XEN_LIBXC) -I $(XEN_XENSTORE)
 
-CFLAGS += -Werror -fno-strict-aliasing
+CFLAGS += -fno-strict-aliasing
 CFLAGS += $(INCLUDES)
 
 # Make gcc generate dependencies.
--- tools/xenmon/Makefile
+++ tools/xenmon/Makefile
@@ -15,7 +15,6 @@
 
 sbindir=/usr/sbin
 
-CFLAGS  += -Werror
 CFLAGS  += -I $(XEN_XC)
 CFLAGS  += -I $(XEN_LIBXC)
 LDFLAGS += -L $(XEN_LIBXC)
--- tools/xenstat/libxenstat/Makefile
+++ tools/xenstat/libxenstat/Makefile
@@ -33,7 +33,7 @@
 OBJECTS-$(CONFIG_SunOS) += src/xenstat_solaris.o
 SONAME_FLAGS=-Wl,$(SONAME_LDFLAG) -Wl,libxenstat.so.$(MAJOR)
 
-WARN_FLAGS=-Wall -Werror
+WARN_FLAGS=-Wall
 
 CFLAGS+=-Isrc -I$(XEN_LIBXC) -I$(XEN_XENSTORE)
 LDFLAGS+=-Lsrc -L$(XEN_XENSTORE)/ -L$(XEN_LIBXC)/
--- tools/xenstat/xentop/Makefile
+++ tools/xenstat/xentop/Makefile
@@ -23,7 +23,7 @@
 man1dir=$(mandir)/man1
 sbindir=$(prefix)/sbin
 
-CFLAGS += -DGCC_PRINTF -Wall -Werror -I$(XEN_LIBXENSTAT)
+CFLAGS += -DGCC_PRINTF -Wall -I$(XEN_LIBXENSTAT)
 LDFLAGS += -L$(XEN_LIBXENSTAT)
 LDLIBS += -lxenstat $(CURSES_LIBS) $(SOCKET_LIBS)
 CFLAGS += -DHOST_$(XEN_OS)
--- tools/xenstore/Makefile
+++ tools/xenstore/Makefile
@@ -6,7 +6,6 @@
 MINOR = 0
 
 PROFILE=#-pg
-BASECFLAGS=-Werror
 # Make gcc generate dependencies.
 BASECFLAGS += -Wp,-MD,.$(@F).d
 PROG_DEP = .*.d
--- tools/xentrace/Makefile
+++ tools/xentrace/Makefile
@@ -1,8 +1,6 @@
 XEN_ROOT=../..
 include $(XEN_ROOT)/tools/Rules.mk
 
-CFLAGS  += -Werror
-
 CFLAGS  += -I $(XEN_XC)
 CFLAGS  += -I $(XEN_LIBXC)
 
--- xen/arch/ia64/Rules.mk
+++ xen/arch/ia64/Rules.mk
@@ -52,7 +52,7 @@
 CFLAGS += -DCONFIG_XEN_IA64_TLBFLUSH_CLOCK
 endif
 ifeq ($(no_warns),y)
-CFLAGS	+= -Wa,--fatal-warnings -Werror -Wno-uninitialized
+CFLAGS	+= -Wa,--fatal-warnings -Wno-uninitialized
 endif
 
 LDFLAGS := -g
--- xen/arch/powerpc/Rules.mk
+++ xen/arch/powerpc/Rules.mk
@@ -10,7 +10,7 @@
 C_WARNINGS += -Wpacked
 
 CFLAGS := -m64 -ffreestanding -fno-builtin -fno-common -fno-strict-aliasing
-CFLAGS += -iwithprefix include -Wall -Werror -pipe
+CFLAGS += -iwithprefix include -Wall -pipe
 CFLAGS += -I$(BASEDIR)/include
 CFLAGS += -I$(BASEDIR)/include/asm-powerpc/mach-generic
 CFLAGS += -I$(BASEDIR)/include/asm-powerpc/mach-default
--- xen/arch/x86/Rules.mk
+++ xen/arch/x86/Rules.mk
@@ -18,7 +18,7 @@
 endif
 
 CFLAGS += -fno-builtin -fno-common -fno-strict-aliasing
-CFLAGS += -iwithprefix include -Werror -Wno-pointer-arith -pipe
+CFLAGS += -iwithprefix include -Wno-pointer-arith -pipe
 CFLAGS += -I$(BASEDIR)/include 
 CFLAGS += -I$(BASEDIR)/include/asm-x86/mach-generic
 CFLAGS += -I$(BASEDIR)/include/asm-x86/mach-default