--- a/CPP/7zip/7zip_gcc.mak
+++ b/CPP/7zip/7zip_gcc.mak
@@ -24,7 +24,7 @@ PROGPATH_STATIC = $(O)/$(PROG)s
 
 
 ifneq ($(CC), xlc)
-CFLAGS_WARN_WALL = -Werror -Wall -Wextra
+CFLAGS_WARN_WALL = -Wall -Wextra
 endif
 
 # for object file
@@ -45,12 +45,12 @@ CFLAGS_DEBUG = -g
 else
 CFLAGS_DEBUG = -DNDEBUG
 ifneq ($(CC), $(CROSS_COMPILE)clang)
-LFLAGS_STRIP = -s
+LFLAGS_STRIP =
 endif
 endif
 
 # CFLAGS_BASE_LIST = -S
-CFLAGS_BASE = -O2 $(CFLAGS_BASE_LIST) $(CFLAGS_WARN_WALL) $(CFLAGS_WARN) \
+CFLAGS_BASE = $(CFLAGS_BASE_LIST) $(CFLAGS_WARN_WALL) $(CFLAGS_WARN) \
  $(CFLAGS_DEBUG) -D_REENTRANT -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE \
  -fPIC
 
@@ -169,7 +169,7 @@ endif
 
 
 
-CFLAGS = $(MY_ARCH_2) $(LOCAL_FLAGS) $(CFLAGS_BASE2) $(CFLAGS_BASE) $(FLAGS_FLTO) $(CC_SHARED) -o $@
+CFLAGS += $(MY_ARCH_2) $(LOCAL_FLAGS) $(CFLAGS_BASE2) $(CFLAGS_BASE) $(FLAGS_FLTO) $(CC_SHARED) -o $@
 
 
 ifdef IS_MINGW
@@ -1361,7 +1361,7 @@ predef_cc:
 	$(CC) $(CFLAGS) -E $(SHOW_PREDEF)  ../../../../C/CpuArch.c > predef_cc_log
 #	$(CC) $(CFLAGS) -E -dM -  < /dev/null
 predef_cxx:
-	$(CXX) $(CFLAGS) -E $(SHOW_PREDEF) ../../../Common/CrcReg.cpp  > predef_cxx_log
+	$(CXX) $(CXXFLAGS) -E $(SHOW_PREDEF) ../../../Common/CrcReg.cpp  > predef_cxx_log
 
 predef: predef_cc predef_cxx