diff --git a/xs/src/libslic3r/PrintConfig.cpp b/xs/src/libslic3r/PrintConfig.cpp
index a505bd888f..90af82fbdf 100644
--- a/xs/src/libslic3r/PrintConfig.cpp
+++ b/xs/src/libslic3r/PrintConfig.cpp
@@ -1035,7 +1035,7 @@ PrintConfigDef::PrintConfigDef()
 
     def = this->add("start_gcode", coString);
     def->label = "Start G-code";
-    def->tooltip = "This start procedure is inserted at the beginning, after bed has reached the target temperature and extruder just started heating, and before extruder has finished heating. If Slic3r detects M104 or M190 in your custom codes, such commands will not be prepended automatically so you're free to customize the order of heating commands and other custom actions. Note that you can use placeholder variables for all Slic3r settings, so you can put a \"M109 S[first_layer_temperature]\" command wherever you want.";
+    def->tooltip = "This start procedure is inserted at the beginning, after bed has reached the target temperature and extruder just started heating, and before extruder has finished heating. If Slic3r detects M104, M109, M140 or M190 in your custom codes, such commands will not be prepended automatically so you're free to customize the order of heating commands and other custom actions. Note that you can use placeholder variables for all Slic3r settings, so you can put a \"M109 S[first_layer_temperature]\" command wherever you want.";
     def->cli = "start-gcode=s";
     def->multiline = true;
     def->full_width = true;