diff --git a/src/libslic3r/GCode.cpp b/src/libslic3r/GCode.cpp
index c9cea8f83..b827b25d2 100644
--- a/src/libslic3r/GCode.cpp
+++ b/src/libslic3r/GCode.cpp
@@ -4622,7 +4622,7 @@ ExtrusionPaths GCode::set_speed_transition(ExtrusionPaths &paths)
 
 void GCode::smooth_speed_discontinuity_area(ExtrusionPaths &paths) {
 
-    if (paths.size() <= 1)
+    if (paths.size() <= 1 || this->config().smooth_coefficient == 0)
         return;
 
     //step 1 merge same speed path
diff --git a/src/libslic3r/PrintConfig.cpp b/src/libslic3r/PrintConfig.cpp
index 7025d021b..69be58c8d 100644
--- a/src/libslic3r/PrintConfig.cpp
+++ b/src/libslic3r/PrintConfig.cpp
@@ -2691,8 +2691,9 @@ void PrintConfigDef::init_fff_params()
     def           = this->add("smooth_coefficient", coFloat);
     def->label    = L("Smooth coefficient");
     def->category = L("Quality");
-    def->tooltip  = L("The smaller the number, the longer the speed transition path.");
+    def->tooltip  = L("The smaller the number, the longer the speed transition path. 0 means not apply.");
     def->mode     = comAdvanced;
+    def->min      = 0;
     def->set_default_value(new ConfigOptionFloat(80));
 
     def = this->add("wall_filament", coInt);