diff --git a/Marlin/src/gcode/bedlevel/abl/G29.cpp b/Marlin/src/gcode/bedlevel/abl/G29.cpp
index e4269579fd3b6cce242d81fd85017a406cf47944..dc0b5cf4ca5a92b5633646c947cd4e5155bd9a51 100644
--- a/Marlin/src/gcode/bedlevel/abl/G29.cpp
+++ b/Marlin/src/gcode/bedlevel/abl/G29.cpp
@@ -260,7 +260,8 @@ void GcodeSuite::G29() {
 
     #if ENABLED(AUTO_BED_LEVELING_BILINEAR)
 
-      if (parser.seen('W')) {
+      const bool seen_w = parser.seen('W');
+      if (seen_w) {
         if (!leveling_is_valid()) {
           SERIAL_ERROR_START();
           SERIAL_ERRORLNPGM("No bilinear grid");
@@ -298,10 +299,14 @@ void GcodeSuite::G29() {
         return;
       } // parser.seen('W')
 
+    #else
+
+      constexpr bool seen_w = false;
+
     #endif
 
     // Jettison bed leveling data
-    if (parser.seen('J')) {
+    if (!seen_w && parser.seen('J')) {
       reset_bed_level();
       return;
     }