diff --git a/Marlin/src/module/configuration_store.cpp b/Marlin/src/module/configuration_store.cpp
index bcdb0e4a8..efd9daded 100644
--- a/Marlin/src/module/configuration_store.cpp
+++ b/Marlin/src/module/configuration_store.cpp
@@ -323,7 +323,7 @@ typedef struct SettingsDataStruct {
   //
   // LIN_ADVANCE
   //
-  float planner_extruder_advance_K[EXTRUDERS];          // M900 K  planner.extruder_advance_K
+  float planner_extruder_advance_K[_MAX(EXTRUDERS, 1)]; // M900 K  planner.extruder_advance_K
 
   //
   // HAS_MOTOR_CURRENT_PWM