diff --git a/Firmware/Marlin_main.cpp b/Firmware/Marlin_main.cpp
index 2e8cff9a..aacb73c0 100755
--- a/Firmware/Marlin_main.cpp
+++ b/Firmware/Marlin_main.cpp
@@ -3001,7 +3001,7 @@ template<typename T>
 static T gcode_M600_filament_change_z_shift()
 {
 #ifdef FILAMENTCHANGE_ZADD
-	static_assert(Z_MAX_POS < (255 - FILAMENTCHANGE_ZADD), "Z-range too high, change the T type from uint8_t to uint16_t");
+	static_assert(Z_MAX_POS < (Z_MAX_POS + 45 - FILAMENTCHANGE_ZADD), "Z-range too high, change the T type from uint8_t to uint16_t");
 	// avoid floating point arithmetics when not necessary - results in shorter code
 	T ztmp = T( current_position[Z_AXIS] );
 	T z_shift = 0;
diff --git a/Firmware/fsensor.cpp b/Firmware/fsensor.cpp
index 840c5260..20078912 100755
--- a/Firmware/fsensor.cpp
+++ b/Firmware/fsensor.cpp
@@ -543,7 +543,7 @@ void fsensor_enque_M600(){
 	// 8bit arithmetics in fsensor_clamp_z is 10B shorter than 16bit (not talking about float ;) ) 
 	// The compile-time static_assert here ensures, that the computation gets enough bits in case of Z-range too high,
 	// i.e. makes the user change the data type, which also results in larger code
-	static_assert(Z_MAX_POS < (255 - FILAMENTCHANGE_ZADD), "Z-range too high, change fsensor_clamp_z<uint8_t> to <uint16_t>");
+	static_assert(Z_MAX_POS < (Z_MAX_POS + 45 - FILAMENTCHANGE_ZADD), "Z-range too high, change fsensor_clamp_z<uint8_t> to <uint16_t>");
 	sprintf_P(buf, gcodeMove, fsensor_clamp_z<uint8_t>(current_position[Z_AXIS]) );
 	enquecommand_front(buf, false);
 }