diff --git a/xs/src/libslic3r/PrintGCode.cpp b/xs/src/libslic3r/PrintGCode.cpp
index 9ba01209a..724679d0e 100644
--- a/xs/src/libslic3r/PrintGCode.cpp
+++ b/xs/src/libslic3r/PrintGCode.cpp
@@ -130,11 +130,12 @@ PrintGCode::output()
 
     // Apply gcode math to start gcode
     fh << apply_math(gcodegen.placeholder_parser->process(config.start_gcode.value));
-
-    auto filament_extruder {0U};
-    for(const auto& start_gcode : config.start_filament_gcode.values) {
-        gcodegen.placeholder_parser->set("filament_extruder_id", filament_extruder++);
-        fh << apply_math(gcodegen.placeholder_parser->process(start_gcode));
+    {
+        auto filament_extruder {0U};
+        for(const auto& start_gcode : config.start_filament_gcode.values) {
+            gcodegen.placeholder_parser->set("filament_extruder_id", filament_extruder++);
+            fh << apply_math(gcodegen.placeholder_parser->process(start_gcode));
+        }
     }
     
     if (include_start_extruder_temp) this->_print_first_layer_temperature(1);
@@ -281,10 +282,12 @@ PrintGCode::output()
     // Write end commands to file.
     fh << gcodegen.retract(); // TODO: process this retract through PressureRegulator in order to discharge fully
 
-    auto filament_extruder {0U};
-    for(const auto& end_gcode : config.end_filament_gcode.values) {
-        gcodegen.placeholder_parser->set("filament_extruder_id", filament_extruder++);
-        fh << apply_math(gcodegen.placeholder_parser->process(end_gcode));
+    {
+        auto filament_extruder {0U};
+        for(const auto& end_gcode : config.end_filament_gcode.values) {
+            gcodegen.placeholder_parser->set("filament_extruder_id", filament_extruder++);
+            fh << apply_math(gcodegen.placeholder_parser->process(end_gcode));
+        }
     }
 
     fh << apply_math(gcodegen.placeholder_parser->process(config.end_gcode));