diff --git a/g2core/gcode_parser.cpp b/g2core/gcode_parser.cpp
index 60e9956c..2005f9e9 100644
--- a/g2core/gcode_parser.cpp
+++ b/g2core/gcode_parser.cpp
@@ -1140,7 +1140,7 @@ static stat_t _execute_gcode_block_marlin()
             if (gf.S_word) { temp = gv.S_word; }
             if (gf.P_word) { temp = gv.P_word; }            // we treat them the same, for now
 
-            uint8_t tool = (gv.next_action == NEXT_ACTION_MARLIN_SET_EXTRUDER_TEMP) ? cm.gm.tool_select : 2; // heat bed is 2 here, normally 3
+            uint8_t tool = (gv.next_action == NEXT_ACTION_MARLIN_SET_EXTRUDER_TEMP) ? cm.gm.tool_select : 3;
             ritorno(marlin_set_temperature(tool, temp, gf.marlin_wait_for_temp));
 
             gf.P_word = false;
diff --git a/g2core/marlin_compatibility.cpp b/g2core/marlin_compatibility.cpp
index 667d5d88..964df8bb 100644
--- a/g2core/marlin_compatibility.cpp
+++ b/g2core/marlin_compatibility.cpp
@@ -330,7 +330,7 @@ stat_t marlin_set_temperature(uint8_t tool, float temperature, bool wait) {
     if (MarlinSetTempState::Idle != set_temp_state) {
         return (STAT_BUFFER_FULL_FATAL); // we shouldn't be here
     }
-    if ((tool < 1) || (tool > 2)) {
+    if ((tool < 1) || (tool > 3)) {
         return STAT_INPUT_VALUE_RANGE_ERROR;
     }