diff --git a/src/libslic3r/GCode/PreviewData.cpp b/src/libslic3r/GCode/PreviewData.cpp
index eecabe718..874a4d2ec 100644
--- a/src/libslic3r/GCode/PreviewData.cpp
+++ b/src/libslic3r/GCode/PreviewData.cpp
@@ -241,6 +241,7 @@ void GCodePreviewData::reset()
     ranges.width.reset();
     ranges.height.reset();
     ranges.feedrate.reset();
+    ranges.fan_speed.reset();
     ranges.volumetric_rate.reset();
     extrusion.layers.clear();
     travel.polylines.clear();