diff --git a/Marlin/Marlin_main.cpp b/Marlin/Marlin_main.cpp
index 5ad45ef2ecb4c9b34dff3156fa3e4eac0684083f..61d4247d83c90ed5af4e2596850a0fee1cf98d61 100644
--- a/Marlin/Marlin_main.cpp
+++ b/Marlin/Marlin_main.cpp
@@ -1690,7 +1690,7 @@ inline void gcode_G2_G3(bool clockwise) {
  * G4: Dwell S<seconds> or P<milliseconds>
  */
 inline void gcode_G4() {
-  unsigned long codenum;
+  unsigned long codenum=0;
 
   LCD_MESSAGEPGM(MSG_DWELL);