diff --git a/Marlin/Configuration_adv.h b/Marlin/Configuration_adv.h
index b1659407f8..0d578749e2 100644
--- a/Marlin/Configuration_adv.h
+++ b/Marlin/Configuration_adv.h
@@ -1258,7 +1258,7 @@
 
   // Default M20 File Listing behavior
   #if ENABLED(LONG_FILENAME_HOST_SUPPORT)
-    #define M20_REPORT_DOS_FILENAMES      // Include DOS 8.3 filenames in listings by default
+    //#define M20_DEFER_DOS_FILENAMES     // Hide DOS 8.3 filenames in listings by default
     //#define M20_REPORT_LONG_FILENAMES   // Include long filenames in listings by default
   #endif
 
diff --git a/Marlin/src/gcode/sd/M20.cpp b/Marlin/src/gcode/sd/M20.cpp
index f4f09b73fe..207b541e3e 100644
--- a/Marlin/src/gcode/sd/M20.cpp
+++ b/Marlin/src/gcode/sd/M20.cpp
@@ -33,7 +33,7 @@
 void GcodeSuite::M20() {
   if (card.flag.mounted) {
     card.ls(
-      parser.boolval('S', TERN1(M20_REPORT_DOS_FILENAMES)),
+      parser.boolval('S', DISABLED(M20_DEFER_DOS_FILENAMES)),
       parser.boolval('L', ENABLED(M20_REPORT_LONG_FILENAMES))
     );
     if (DISABLED(LONG_FILENAME_HOST_SUPPORT) && parser.boolval('L'))