diff --git a/lauxlib.h b/lauxlib.h
index 59fef6a..df3de4f 100644
--- a/lauxlib.h
+++ b/lauxlib.h
@@ -158,6 +158,18 @@
 
 
 /*
+** Internal assertions for in-house debugging
+*/
+#if defined LUAI_ASSERT
+#include <assert.h>
+#define lua_assert(c)	assert(c)
+#else
+#define lua_assert(x)	((void)0)
+#endif
+
+
+
+/*
 ** {======================================================
 ** Generic Buffer manipulation
 ** =======================================================
diff --git a/lualib.h b/lualib.h
index eb08b53..2625529 100644
--- a/lualib.h
+++ b/lualib.h
@@ -49,10 +49,4 @@
 LUALIB_API void (luaL_openlibs) (lua_State *L);
 
 
-
-#if !defined(lua_assert)
-#define lua_assert(x)	((void)0)
-#endif
-
-
 #endif