diff --git a/Marlin/src/gcode/bedlevel/abl/G29.cpp b/Marlin/src/gcode/bedlevel/abl/G29.cpp
index c48c693b78..9c5907a5cc 100644
--- a/Marlin/src/gcode/bedlevel/abl/G29.cpp
+++ b/Marlin/src/gcode/bedlevel/abl/G29.cpp
@@ -419,7 +419,7 @@ G29_TYPE GcodeSuite::G29() {
 
     #if ENABLED(AUTO_BED_LEVELING_BILINEAR)
 
-      if (TERN_(PROBE_MANUALLY, !no_action)
+      if (TERN1(PROBE_MANUALLY, !no_action)
         && (gridSpacing != bilinear_grid_spacing || probe_position_lf != bilinear_start)
       ) {
         // Reset grid to 0.0 or "not probed". (Also disables ABL)