diff --git a/Marlin/Marlin.h b/Marlin/Marlin.h
index 740c7bc79..f05e23211 100644
--- a/Marlin/Marlin.h
+++ b/Marlin/Marlin.h
@@ -448,10 +448,6 @@ void report_current_position();
                filament_change_load_length[EXTRUDERS];
 #endif
 
-#if ENABLED(PID_EXTRUSION_SCALING)
-  extern int lpq_len;
-#endif
-
 #if HAS_POWER_SWITCH
   extern bool powersupply_on;
   #define PSU_PIN_ON()  do{ OUT_WRITE(PS_ON_PIN, PS_ON_AWAKE); powersupply_on = true; }while(0)
diff --git a/Marlin/Marlin_main.cpp b/Marlin/Marlin_main.cpp
index d7c6ccc0d..e590c73d5 100644
--- a/Marlin/Marlin_main.cpp
+++ b/Marlin/Marlin_main.cpp
@@ -696,10 +696,6 @@ static bool send_ok[BUFSIZE];
   bool chdkActive = false;
 #endif
 
-#if ENABLED(PID_EXTRUSION_SCALING)
-  int lpq_len = 20;
-#endif
-
 #if ENABLED(HOST_KEEPALIVE_FEATURE)
   MarlinBusyState busy_state = NOT_BUSY;
   static millis_t next_busy_signal_ms = 0;
@@ -9598,7 +9594,7 @@ inline void gcode_M226() {
    * With PID_EXTRUSION_SCALING:
    *
    *   C[float] Kc term
-   *   L[float] LPQ length
+   *   L[int]   LPQ length
    */
   inline void gcode_M301() {
 
@@ -9612,8 +9608,9 @@ inline void gcode_M226() {
       if (parser.seen('D')) PID_PARAM(Kd, e) = scalePID_d(parser.value_float());
       #if ENABLED(PID_EXTRUSION_SCALING)
         if (parser.seen('C')) PID_PARAM(Kc, e) = parser.value_float();
-        if (parser.seen('L')) lpq_len = parser.value_float();
-        NOMORE(lpq_len, LPQ_MAX_LEN);
+        if (parser.seen('L')) thermalManager.lpq_len = parser.value_float();
+        NOMORE(thermalManager.lpq_len, LPQ_MAX_LEN);
+        NOLESS(thermalManager.lpq_len, 0);
       #endif
 
       thermalManager.updatePID();
diff --git a/Marlin/configuration_store.cpp b/Marlin/configuration_store.cpp
index b78b53aa5..09d753966 100644
--- a/Marlin/configuration_store.cpp
+++ b/Marlin/configuration_store.cpp
@@ -73,6 +73,10 @@
   #include "fwretract.h"
 #endif
 
+#if ENABLED(PID_EXTRUSION_SCALING)
+  #define LPQ_LEN thermalManager.lpq_len
+#endif
+
 #pragma pack(push, 1) // No padding between variables
 
 typedef struct PID { float Kp, Ki, Kd; } PID;
@@ -183,7 +187,7 @@ typedef struct SettingsDataStruct {
   //
   PIDC hotendPID[MAX_EXTRUDERS];                        // M301 En PIDC / M303 En U
 
-  int lpq_len;                                          // M301 L
+  int16_t lpq_len;                                      // M301 L
 
   //
   // PIDTEMPBED
@@ -609,9 +613,9 @@ void MarlinSettings::postprocess() {
     _FIELD_TEST(lpq_len);
 
     #if DISABLED(PID_EXTRUSION_SCALING)
-      int lpq_len = 20;
+      const int16_t LPQ_LEN = 20;
     #endif
-    EEPROM_WRITE(lpq_len);
+    EEPROM_WRITE(LPQ_LEN);
 
     #if DISABLED(PIDTEMPBED)
       dummy = DUMMY_PID_VALUE;
@@ -1213,9 +1217,9 @@ void MarlinSettings::postprocess() {
       _FIELD_TEST(lpq_len);
 
       #if DISABLED(PID_EXTRUSION_SCALING)
-        int lpq_len;
+        int16_t LPQ_LEN;
       #endif
-      EEPROM_READ(lpq_len);
+      EEPROM_READ(LPQ_LEN);
 
       //
       // Heated Bed PID
@@ -1808,7 +1812,7 @@ void MarlinSettings::reset() {
       #endif
     }
     #if ENABLED(PID_EXTRUSION_SCALING)
-      lpq_len = 20; // default last-position-queue size
+      thermalManager.lpq_len = 20; // default last-position-queue size
     #endif
   #endif // PIDTEMP
 
@@ -2271,7 +2275,7 @@ void MarlinSettings::reset() {
               SERIAL_ECHOPAIR(" D", unscalePID_d(PID_PARAM(Kd, e)));
               #if ENABLED(PID_EXTRUSION_SCALING)
                 SERIAL_ECHOPAIR(" C", PID_PARAM(Kc, e));
-                if (e == 0) SERIAL_ECHOPAIR(" L", lpq_len);
+                if (e == 0) SERIAL_ECHOPAIR(" L", thermalManager.lpq_len);
               #endif
               SERIAL_EOL();
             }
@@ -2286,7 +2290,7 @@ void MarlinSettings::reset() {
           SERIAL_ECHOPAIR(" D", unscalePID_d(PID_PARAM(Kd, 0)));
           #if ENABLED(PID_EXTRUSION_SCALING)
             SERIAL_ECHOPAIR(" C", PID_PARAM(Kc, 0));
-            SERIAL_ECHOPAIR(" L", lpq_len);
+            SERIAL_ECHOPAIR(" L", thermalManager.lpq_len);
           #endif
           SERIAL_EOL();
         }
diff --git a/Marlin/temperature.cpp b/Marlin/temperature.cpp
index 6a1ae0855..4ee0ed3ac 100644
--- a/Marlin/temperature.cpp
+++ b/Marlin/temperature.cpp
@@ -237,6 +237,10 @@ uint8_t Temperature::soft_pwm_amount[HOTENDS];
   uint8_t Temperature::ADCKey_count = 0;
 #endif
 
+#if ENABLED(PID_EXTRUSION_SCALING)
+  int16_t Temperature::lpq_len; // Initialized in configuration_store
+#endif
+
 #if HAS_PID_HEATING
 
   /**
@@ -666,14 +670,14 @@ float Temperature::get_pid_output(const int8_t e) {
         #if ENABLED(PID_EXTRUSION_SCALING)
           cTerm[HOTEND_INDEX] = 0;
           if (_HOTEND_TEST) {
-            long e_position = stepper.position(E_AXIS);
+            const long e_position = stepper.position(E_AXIS);
             if (e_position > last_e_position) {
               lpq[lpq_ptr] = e_position - last_e_position;
               last_e_position = e_position;
             }
-            else {
+            else
               lpq[lpq_ptr] = 0;
-            }
+
             if (++lpq_ptr >= lpq_len) lpq_ptr = 0;
             cTerm[HOTEND_INDEX] = (lpq[lpq_ptr] * planner.steps_to_mm[E_AXIS]) * PID_PARAM(Kc, HOTEND_INDEX);
             pid_output += cTerm[HOTEND_INDEX];
diff --git a/Marlin/temperature.h b/Marlin/temperature.h
index 27358bac6..247f27338 100644
--- a/Marlin/temperature.h
+++ b/Marlin/temperature.h
@@ -304,6 +304,10 @@ class Temperature {
       static uint8_t ADCKey_count;
     #endif
 
+    #if ENABLED(PID_EXTRUSION_SCALING)
+      static int16_t lpq_len;
+    #endif
+
     /**
      * Instance Methods
      */