diff --git a/src/libslic3r/GCode/GCodeProcessor.hpp b/src/libslic3r/GCode/GCodeProcessor.hpp
index 88aa94e217..19bee0b29f 100644
--- a/src/libslic3r/GCode/GCodeProcessor.hpp
+++ b/src/libslic3r/GCode/GCodeProcessor.hpp
@@ -73,7 +73,7 @@ namespace Slic3r {
         PrintEstimatedStatistics() { reset(); }
 
         void reset() {
-            for (auto m : modes) {
+            for (Mode &m : modes) {
                 m.reset();
             }
             volumes_per_color_change.clear();