diff --git a/src/libslic3r/GCode.cpp b/src/libslic3r/GCode.cpp
index 1d7dc09f0e..0236125186 100644
--- a/src/libslic3r/GCode.cpp
+++ b/src/libslic3r/GCode.cpp
@@ -258,7 +258,7 @@ static std::vector<Vec2d> get_path_of_change_filament(const Print& print)
 
         unsigned int extruder_id = gcodegen.writer().extruder()->id();
         const auto& filament_idle_temp = gcodegen.config().idle_temperature;
-        if (filament_idle_temp.get_at(extruder_id) > 0) {
+        if (filament_idle_temp.get_at(extruder_id) == 0) {
             // There is no idle temperature defined in filament settings.
             // Use the delta value from print config.
             if (gcodegen.config().standby_temperature_delta.value != 0) {
diff --git a/src/libslic3r/Print.cpp b/src/libslic3r/Print.cpp
index 5e687cbbd4..3650b4ef90 100644
--- a/src/libslic3r/Print.cpp
+++ b/src/libslic3r/Print.cpp
@@ -1162,10 +1162,10 @@ StringObjectException Print::validate(StringObjectException *warning, Polygons*
 
         if (! m_config.use_relative_e_distances)
             return { L("The Wipe Tower is currently only supported with the relative extruder addressing (use_relative_e_distances=1).") };
-        if (m_config.ooze_prevention)
-            return { L("Ooze prevention is currently not supported with the prime tower enabled.") };
 
-        // BBS: remove following logic and _L()
+        if (m_config.ooze_prevention && m_config.single_extruder_multi_material)
+            return {L("Ooze prevention is only supported with the wipe tower when 'single_extruder_multi_material' is off.")};
+            
 #if 0
         if (m_config.gcode_flavor != gcfRepRapSprinter && m_config.gcode_flavor != gcfRepRapFirmware &&
             m_config.gcode_flavor != gcfRepetier && m_config.gcode_flavor != gcfMarlinLegacy && m_config.gcode_flavor != gcfMarlinFirmware)
diff --git a/src/libslic3r/PrintConfig.cpp b/src/libslic3r/PrintConfig.cpp
index 4045f41e33..d6f5cd278c 100644
--- a/src/libslic3r/PrintConfig.cpp
+++ b/src/libslic3r/PrintConfig.cpp
@@ -4073,7 +4073,7 @@ void PrintConfigDef::init_fff_params()
     // TRN PrintSettings : "Ooze prevention" > "Temperature variation"
     def->tooltip = L("Temperature difference to be applied when an extruder is not active. "
                      "The value is not used when 'idle_temperature' in filament settings "
-                     "is defined.");
+                     "is set to non zero value.");
     def->sidetext = "∆°C";
     def->min = -max_temp;
     def->max = max_temp;