diff --git a/Marlin/Marlin.h b/Marlin/Marlin.h
index ded8b1f50e..1e14fbf1c4 100644
--- a/Marlin/Marlin.h
+++ b/Marlin/Marlin.h
@@ -35,13 +35,11 @@
 
 #include "MarlinConfig.h"
 
-#include "fastio.h"
-
 #include "enum.h"
+#include "types.h"
+#include "fastio.h"
 #include "utility.h"
 
-typedef unsigned long millis_t;
-
 #ifdef USBCON
   #include "HardwareSerial.h"
   #if ENABLED(BLUETOOTH)
diff --git a/Marlin/utility.cpp b/Marlin/utility.cpp
index 385fe3d391..0285219c40 100644
--- a/Marlin/utility.cpp
+++ b/Marlin/utility.cpp
@@ -21,9 +21,10 @@
  */
 
 #include "Marlin.h"
+#include "utility.h"
 #include "temperature.h"
 
-void safe_delay(uint16_t ms) {
+void safe_delay(millis_t ms) {
   while (ms > 50) {
     ms -= 50;
     delay(50);
diff --git a/Marlin/utility.h b/Marlin/utility.h
index 8bb3a9b8b6..8ca70dbf83 100644
--- a/Marlin/utility.h
+++ b/Marlin/utility.h
@@ -20,4 +20,9 @@
  *
  */
 
-void safe_delay(uint16_t ms);
+#ifndef __UTILITY_H__
+#define __UTILITY_H__
+
+void safe_delay(millis_t ms);
+
+#endif