diff --git a/sol/compatibility/5.1.0.h b/sol/compatibility/5.1.0.h
index 7484aedf..45225a0a 100644
--- a/sol/compatibility/5.1.0.h
+++ b/sol/compatibility/5.1.0.h
@@ -158,7 +158,7 @@ inline const char* kepler_lua_compat_get_string(lua_State* L, void* ud, size_t*
     return ls->s;
 }
 
-#if !defined(SOL_LUAJIT) || ((SOL_LUAJIT_VERSION - 20100) <= 0)
+#if !defined(SOL_LUAJIT) || (SOL_LUAJIT_VERSION < 20100)
 // Luajit 2.1.0 has this function already
 
 inline int luaL_loadbufferx(lua_State* L, const char* buff, size_t size, const char* name, const char*) {
@@ -172,4 +172,4 @@ inline int luaL_loadbufferx(lua_State* L, const char* buff, size_t size, const c
 
 #endif /* Lua 5.1 */
 
-#endif // SOL_5_1_0_H
\ No newline at end of file
+#endif // SOL_5_1_0_H