diff --git a/lualib/Makefile.clang b/lualib/Makefile.clang
index f3131f2..d56a712 100644
--- a/lualib/Makefile.clang
+++ b/lualib/Makefile.clang
@@ -14,7 +14,7 @@ CC= clang-16
 # And if __ISO_C_VISIBLE=1999 then LLONG_MAX is defined in ckb-c-stdlib
 # See https://github.com/nervosnetwork/ckb-c-stdlib/blob/efe1fe6b3cdda12e248e25664f5c04cbf7876265/libc/limits.h#L94
 # and https://github.com/nervosnetwork/ckb-lua/blob/b71d44288e8fb085074d3af056b359b8c6c22afa/lualib/luaconf.h#L502
-CFLAGS= --target=riscv64 -march=rv64imc_zba_zbb_zbc_zbs -Ic-stdlib -I../include/ckb-c-stdlib -I../include/ckb-c-stdlib/libc -O3 -Wall -Wextra -D__ISO_C_VISIBLE=1999 -DLUA_COMPAT_5_3 -ULUA_USE_LINUX -ULUA_USE_POSIX -fno-builtin-printf -fno-builtin-memcmp -nostdinc -nostdlib $(SYSCFLAGS) $(MYCFLAGS)
+CFLAGS= --target=riscv64 -march=rv64imc_zba_zbb_zbc_zbs -Ic-stdlib -I../include/ckb-c-stdlib -I../include/ckb-c-stdlib/libc -O3 -Wall -Wextra -D__ISO_C_VISIBLE=1999 -DCKB_DECLARATION_ONLY -DCKB_MALLOC_DECLARATION_ONLY -DLUA_COMPAT_5_3 -ULUA_USE_LINUX -ULUA_USE_POSIX -fno-builtin-printf -fno-builtin-memcmp -nostdinc -nostdlib $(SYSCFLAGS) $(MYCFLAGS)
 LDFLAGS= $(SYSLDFLAGS) $(MYLDFLAGS)
 LIBS= -lm $(SYSLIBS) $(MYLIBS)
 
diff --git a/lualib/c-stdlib/my_stdio.h b/lualib/c-stdlib/my_stdio.h
index 7133fb0..a996e66 100644
--- a/lualib/c-stdlib/my_stdio.h
+++ b/lualib/c-stdlib/my_stdio.h
@@ -22,9 +22,9 @@ typedef struct FILE {
     uint32_t offset;
 } FILE;
 
-FILE *stdin;
-FILE *stdout;
-FILE *stderr;
+extern FILE *stdin;
+extern FILE *stdout;
+extern FILE *stderr;
 
 int remove(const char *__filename);
 
diff --git a/lualib/c-stdlib/my_string.h b/lualib/c-stdlib/my_string.h
index cacdd7c..ac94622 100644
--- a/lualib/c-stdlib/my_string.h
+++ b/lualib/c-stdlib/my_string.h
@@ -2,6 +2,7 @@
 #define LUA_C_STDLIB_STRING_H_
 
 #include <stddef.h>
+#include <string.h>
 
 char *strchr (const char *, int);
 int strncmp(const char *_l, const char *_r, size_t n);