diff --git a/libraries/AP_Scripting/lua_scripts.cpp b/libraries/AP_Scripting/lua_scripts.cpp
index a3e587c53e6a0..03c94921136f9 100644
--- a/libraries/AP_Scripting/lua_scripts.cpp
+++ b/libraries/AP_Scripting/lua_scripts.cpp
@@ -255,10 +255,13 @@ void lua_scripts::load_all_scripts_in_dir(lua_State *L, const char *dirname) {
     if (dirname == nullptr) {
         return;
     }
-
     auto *d = AP::FS().opendir(dirname);
     if (d == nullptr) {
-        GCS_SEND_TEXT(MAV_SEVERITY_WARNING, "Lua: open directory (%s) failed", dirname);
+        // this disk_space check will return 0 if we don't have a real
+        // filesystem (ie. no Posix or FatFs).  Do not warn in this case.
+        if (AP::FS().disk_space(dirname) != 0) {
+            GCS_SEND_TEXT(MAV_SEVERITY_WARNING, "Lua: open directory (%s) failed", dirname);
+        }
         return;
     }