diff --git a/include/types/hlua.h b/include/types/hlua.h
index a923624..34bd648 100644
--- a/include/types/hlua.h
+++ b/include/types/hlua.h
@@ -32,6 +32,8 @@
 #define HLUA_F_AS_STRING    0x01
 #define HLUA_F_MAY_USE_HTTP 0x02
 
+#define HLUA_CONCAT_BLOCSZ 2048
+
 enum hlua_exec {
 	HLUA_E_OK = 0,
 	HLUA_E_AGAIN,  /* LUA yield, must resume the stack execution later, when
@@ -136,6 +138,11 @@
 	luaL_Buffer b; /* buffer used to prepare strings. */
 };
 
+struct hlua_concat {
+	int size;
+	int len;
+};
+
 #else /* USE_LUA */
 
 /* Empty struct for compilation compatibility */