diff --git a/Marlin/src/module/configuration_store.cpp b/Marlin/src/module/configuration_store.cpp
index b389741b79a9..b97d53662751 100644
--- a/Marlin/src/module/configuration_store.cpp
+++ b/Marlin/src/module/configuration_store.cpp
@@ -1145,7 +1145,7 @@ void MarlinSettings::postprocess() {
         EEPROM_WRITE(planner.extruder_advance_K);
       #else
         dummy = 0;
-        for (uint8_t q = EXTRUDERS; q--;) EEPROM_WRITE(dummy);
+        for (uint8_t q = MIN(EXTRUDERS, 1); q--;) EEPROM_WRITE(dummy);
       #endif
     }
 
@@ -1934,7 +1934,7 @@ void MarlinSettings::postprocess() {
       // Linear Advance
       //
       {
-        float extruder_advance_K[EXTRUDERS];
+        float extruder_advance_K[MIN(EXTRUDERS, 1)];
         _FIELD_TEST(planner_extruder_advance_K);
         EEPROM_READ(extruder_advance_K);
         #if ENABLED(LIN_ADVANCE)
@@ -2554,9 +2554,9 @@ void MarlinSettings::reset() {
   #if ENABLED(LIN_ADVANCE)
     LOOP_L_N(i, EXTRUDERS) {
       planner.extruder_advance_K[i] = LIN_ADVANCE_K;
-    #if ENABLED(EXTRA_LIN_ADVANCE_K)
-      saved_extruder_advance_K[i] = LIN_ADVANCE_K;
-    #endif
+      #if ENABLED(EXTRA_LIN_ADVANCE_K)
+        saved_extruder_advance_K[i] = LIN_ADVANCE_K;
+      #endif
     }
   #endif