diff --git a/include/proto/hlua_fcn.h b/include/proto/hlua_fcn.h
index e4ce5f091..291bd428c 100644
--- a/include/proto/hlua_fcn.h
+++ b/include/proto/hlua_fcn.h
@@ -1,6 +1,8 @@
 #ifndef _PROTO_HLUA_FCN_H
 #define _PROTO_HLUA_FCN_H
 
+int hlua_checkboolean(lua_State *L, int index);
+
 void hlua_class_const_int(lua_State *L, const char *name, int value);
 void hlua_class_const_str(lua_State *L, const char *name, const char *value);
 void hlua_class_function(lua_State *L, const char *name, int (*function)(lua_State *L));
diff --git a/src/hlua_fcn.c b/src/hlua_fcn.c
index 3af4f6e20..cff1e3af9 100644
--- a/src/hlua_fcn.c
+++ b/src/hlua_fcn.c
@@ -41,6 +41,13 @@ static int class_listener_ref;
 
 static struct field stats[STATS_LEN];
 
+int hlua_checkboolean(lua_State *L, int index)
+{
+	if (!lua_isboolean(L, index))
+		luaL_argerror(L, index, "boolean expected");
+	return lua_toboolean(L, index);
+}
+
 /* This function gets a struct field and convert it in Lua
  * variable. The variable is pushed at the top of the stak.
  */