diff --git a/Marlin/src/HAL/LINUX/HAL.h b/Marlin/src/HAL/LINUX/HAL.h
index 2e545e03d6..1c8dbfd4dc 100644
--- a/Marlin/src/HAL/LINUX/HAL.h
+++ b/Marlin/src/HAL/LINUX/HAL.h
@@ -23,7 +23,7 @@
 
 #define CPU_32_BIT
 
-#define F_CPU 100000000
+#define F_CPU 100000000UL
 #define SystemCoreClock F_CPU
 #include <iostream>
 #include <stdint.h>
diff --git a/Marlin/src/HAL/shared/Delay.h b/Marlin/src/HAL/shared/Delay.h
index d98e960848..a48f3f79cf 100644
--- a/Marlin/src/HAL/shared/Delay.h
+++ b/Marlin/src/HAL/shared/Delay.h
@@ -155,7 +155,7 @@
 #endif
 
 // Delay in nanoseconds
-#define DELAY_NS(x) DELAY_CYCLES( (x) * (F_CPU / 1000000UL) / 1000UL )
+#define DELAY_NS(x) DELAY_CYCLES((x) * ((F_CPU) / 1000000UL) / 1000UL)
 
 // Delay in microseconds
-#define DELAY_US(x) DELAY_CYCLES( (x) * (F_CPU / 1000000UL) )
+#define DELAY_US(x) DELAY_CYCLES((x) * ((F_CPU) / 1000000UL))
diff --git a/Marlin/src/gcode/gcode_d.cpp b/Marlin/src/gcode/gcode_d.cpp
index 99968b625a..2fd03144c5 100644
--- a/Marlin/src/gcode/gcode_d.cpp
+++ b/Marlin/src/gcode/gcode_d.cpp
@@ -181,7 +181,7 @@
         // Use a low-level delay that does not rely on interrupts to function
         // Do not spin forever, to avoid thermal risks if heaters are enabled and
         // watchdog does not work.
-        DELAY_US(10000000);
+        for (int i = 10000; i--;) DELAY_US(1000UL);
         ENABLE_ISRS();
         SERIAL_ECHOLNPGM("FAILURE: Watchdog did not trigger board reset.");
       }