diff --git a/Lua/Makefile b/Lua/Makefile
index 3c9a745..0912289 100644
--- a/Lua/Makefile
+++ b/Lua/Makefile
@@ -5,7 +5,8 @@ LUA_DIR=/usr/local
 LUA_INC= $(LUA_DIR)/include
 LUA=lua
 INCS=-I$(LUA_INC)
-CFLAGS=-std=c99 -Werror -D_XOPEN_SOURCE=700 -D_POSIX_C_SOURCE=200809L -flto
+CFLAGS=-std=c11 -Werror -D_XOPEN_SOURCE=700 -D_POSIX_C_SOURCE=200809L -fPIC -flto=auto -fvisibility=hidden \
+			 -fsanitize=signed-integer-overflow -fno-sanitize-recover
 CWARN=-Wall -Wextra
   # -Wpedantic -Wsign-conversion -Wtype-limits -Wunused-result -Wnull-dereference \
 	# -Waggregate-return -Walloc-zero -Walloca -Warith-conversion -Wcast-align -Wcast-align=strict \
diff --git a/Lua/lbp.c b/Lua/lbp.c
index fc6aec0..510826e 100644
--- a/Lua/lbp.c
+++ b/Lua/lbp.c
@@ -22,6 +22,7 @@
 #include "../pattern.h"
 #include "../match.h"
 #include "../printmatch.h"
+#include "../utils.h"
 
 static const char *builtins_source = (
 #include "builtins.h"
@@ -369,7 +370,7 @@ static const luaL_Reg bp_methods[] = {
     {NULL, NULL}
 };
 
-LUALIB_API int luaopen_bp(lua_State *L)
+public LUALIB_API int luaopen_bp(lua_State *L)
 {
     maybe_pat_t maybe_pat = bp_pattern(builtins_source, builtins_source+strlen(builtins_source));
     if (!maybe_pat.success) {
diff --git a/Makefile b/Makefile
index 9d7cdba..ad713dd 100644
--- a/Makefile
+++ b/Makefile
@@ -2,7 +2,8 @@ NAME=bp
 CC=cc
 PREFIX=/usr/local
 SYSCONFDIR=/etc
-CFLAGS=-std=c99 -Werror -D_XOPEN_SOURCE=700 -D_POSIX_C_SOURCE=200809L -flto=auto -fvisibility=hidden
+CFLAGS=-std=c11 -Werror -D_XOPEN_SOURCE=700 -D_POSIX_C_SOURCE=200809L -fPIC -flto=auto -fvisibility=hidden \
+			 -fsanitize=signed-integer-overflow -fno-sanitize-recover
 CWARN=-Wall -Wextra -Wno-format
   # -Wpedantic -Wsign-conversion -Wtype-limits -Wunused-result -Wnull-dereference \
 	# -Waggregate-return -Walloc-zero -Walloca -Warith-conversion -Wcast-align -Wcast-align=strict \
@@ -46,6 +47,7 @@ tags: $(CFILES) bp.c
 
 clean:
 	rm -f $(NAME) $(OBJFILES)
+	@cd Lua && make clean
 
 lua:
 	@cd Lua && make