diff --git a/src/libslic3r/GCode/FanMover.cpp b/src/libslic3r/GCode/FanMover.cpp
index 989e08bdb8a..f82c6471a68 100644
--- a/src/libslic3r/GCode/FanMover.cpp
+++ b/src/libslic3r/GCode/FanMover.cpp
@@ -442,17 +442,20 @@ void FanMover::_process_gcode_line(GCodeReader& reader, const GCodeReader::GCode
         if (line.has(Axis::E)) {
             new_data.e = reader.e();
             if (relative_e) {
-                assert(new_data.e == 0);
                 new_data.de = line.e();
+                // GCode reader doesn't know it's relative extrusion, we have to do it ourself.
+                //assert(new_data.e == 0);
+                new_data.e = 0;
             } else
                 new_data.de = line.dist_E(reader);
         }
         assert(new_data.dx == 0 || reader.x() == new_data.x);
-        assert(new_data.dx == 0 || reader.x() + new_data.dx == line.x());
-        assert(new_data.dy == 0 ||reader.y() == new_data.y);
-        assert(new_data.dy == 0 || reader.y() + new_data.dy == line.y());
-        assert(new_data.de == 0 || reader.e() == new_data.e);
-        assert(new_data.de == 0 || reader.e() + new_data.de == line.e());
+        assert(new_data.dx == 0 || std::abs(reader.x() + new_data.dx - line.x()) < 0.00001f);
+        assert(new_data.dy == 0 || reader.y() == new_data.y);
+        assert(new_data.dy == 0 || std::abs(reader.y() + new_data.dy - line.y()) < 0.00001f);
+        assert(new_data.de == 0 || (relative_e?0:reader.e()) == new_data.e);
+        assert(new_data.de == 0 || std::abs((relative_e?0.f:reader.e()) + new_data.de - line.e()) < 0.00001f);
+        //assert(new_data.de == 0 ||(relative_e?0.f:reader.e()) + new_data.de == line.e());
 
         if (m_current_kickstart.time > 0 && time > 0) {
             m_current_kickstart.time -= time;