diff --git a/src/slic3r/GUI/Field.cpp b/src/slic3r/GUI/Field.cpp
index 454b4874fc..9750095c96 100644
--- a/src/slic3r/GUI/Field.cpp
+++ b/src/slic3r/GUI/Field.cpp
@@ -197,7 +197,7 @@ void Field::get_value_by_opt_type(wxString& str, const bool check_value/* = true
                 show_error(m_parent, _(L("Invalid numeric input.")));
                 set_value(double_to_string(val), true);
             }
-            else if (check_value && (m_opt.sidetext.rfind("mm/s") != std::string::npos && val > m_opt.max ||
+            else if (check_value && ((m_opt.sidetext.rfind("mm/s") != std::string::npos && val > m_opt.max) ||
                      m_opt.sidetext.rfind("mm ") != std::string::npos && val > 1) && 
                      (m_value.empty() || std::string(str.ToUTF8().data()) != boost::any_cast<std::string>(m_value)))
             {
@@ -444,7 +444,7 @@ void TextCtrl::disable() { dynamic_cast<wxTextCtrl*>(window)->Disable(); dynamic
 #ifdef __WXGTK__
 void TextCtrl::change_field_value(wxEvent& event)
 {
-	if (bChangedValueEvent = event.GetEventType()==wxEVT_KEY_UP)
+	if (bChangedValueEvent = (event.GetEventType()==wxEVT_KEY_UP))
 		on_change_field();
     event.Skip();
 };
@@ -768,7 +768,7 @@ void Choice::set_selection()
 		size_t idx = 0;
 		for (auto el : m_opt.enum_values)
 		{
-			if (el.compare(text_value) == 0)
+			if (el == text_value)
 				break;
 			++idx;
 		}
@@ -789,7 +789,7 @@ void Choice::set_selection()
 		size_t idx = 0;
 		for (auto el : m_opt.enum_values)
 		{
-			if (el.compare(text_value) == 0)
+			if (el == text_value)
 				break;
 			++idx;
 		}
@@ -804,7 +804,7 @@ void Choice::set_selection()
 		size_t idx = 0;
 		for (auto el : m_opt.enum_values)
 		{
-			if (el.compare(text_value) == 0)
+			if (el == text_value)
 				break;
 			++idx;
 		}
@@ -813,6 +813,7 @@ void Choice::set_selection()
 			field->SetSelection(idx);
 		break;
 	}
+    default: break;
 	}
 }
 
@@ -823,7 +824,7 @@ void Choice::set_value(const std::string& value, bool change_event)  //! Redunda
 	size_t idx=0;
 	for (auto el : m_opt.enum_values)
 	{
-		if (el.compare(value) == 0)
+		if (el == value)
 			break;
 		++idx;
 	}
@@ -856,7 +857,7 @@ void Choice::set_value(const boost::any& value, bool change_event)
 		auto idx = 0;
 		for (auto el : m_opt.enum_values)
 		{
-			if (el.compare(text_value) == 0)
+			if (el == text_value)
 				break;
 			++idx;
 		}
@@ -887,7 +888,7 @@ void Choice::set_value(const boost::any& value, bool change_event)
 				size_t idx = 0;
 				for (auto el : m_opt.enum_values)
 				{
-					if (el.compare(key) == 0)
+					if (el == key)
 						break;
 					++idx;
 				}
diff --git a/src/slic3r/GUI/GUI_App.cpp b/src/slic3r/GUI/GUI_App.cpp
index 62f3e89c12..f365a0bfbc 100644
--- a/src/slic3r/GUI/GUI_App.cpp
+++ b/src/slic3r/GUI/GUI_App.cpp
@@ -303,8 +303,9 @@ bool GUI_App::on_init_inner()
      * change min hight of object list to the normal min value (15 * wxGetApp().em_unit()) 
      * after first whole Mainframe updating/layouting
      */
-    if (obj_list()->GetMinSize().GetY() > 15 * em_unit())
-        obj_list()->SetMinSize(wxSize(-1, 15 * em_unit()));
+    const int list_min_height = 15 * em_unit();
+    if (obj_list()->GetMinSize().GetY() > list_min_height)
+        obj_list()->SetMinSize(wxSize(-1, list_min_height));
 
     update_mode(); // update view mode after fix of the object_list size
 
@@ -475,8 +476,9 @@ void GUI_App::recreate_GUI()
     * change min hight of object list to the normal min value (15 * wxGetApp().em_unit())
     * after first whole Mainframe updating/layouting
     */
-    if (obj_list()->GetMinSize().GetY() > 15 * em_unit())
-        obj_list()->SetMinSize(wxSize(-1, 15 * em_unit()));
+    const int list_min_height = 15 * em_unit();
+    if (obj_list()->GetMinSize().GetY() > list_min_height)
+        obj_list()->SetMinSize(wxSize(-1, list_min_height));
 
     update_mode();
 
@@ -1088,7 +1090,7 @@ void GUI_App::window_pos_restore(wxTopLevelWindow* window, const std::string &na
 
 void GUI_App::window_pos_sanitize(wxTopLevelWindow* window)
 {
-    unsigned display_idx = wxDisplay::GetFromWindow(window);
+    /*unsigned*/int display_idx = wxDisplay::GetFromWindow(window);
     wxRect display;
     if (display_idx == wxNOT_FOUND) {
         display = wxDisplay(0u).GetClientArea();
diff --git a/src/slic3r/GUI/OptionsGroup.cpp b/src/slic3r/GUI/OptionsGroup.cpp
index c17569c111..c032aac729 100644
--- a/src/slic3r/GUI/OptionsGroup.cpp
+++ b/src/slic3r/GUI/OptionsGroup.cpp
@@ -457,8 +457,9 @@ void ConfigOptionsGroup::Show(const bool show)
 bool ConfigOptionsGroup::update_visibility(ConfigOptionMode mode) {
     if (m_options_mode.empty())
         return true;
-    if (m_grid_sizer->GetEffectiveRowsCount() != m_options_mode.size() &&
-        m_options_mode.size() == 1)
+    int opt_mode_size = m_options_mode.size();
+    if (m_grid_sizer->GetEffectiveRowsCount() != opt_mode_size &&
+        opt_mode_size == 1)
         return m_options_mode[0] <= mode;
 
     Show(true);
@@ -476,7 +477,7 @@ bool ConfigOptionsGroup::update_visibility(ConfigOptionMode mode) {
         coef+= cols;
 	}
 
-    if (hidden_row_cnt == m_options_mode.size()) {
+    if (hidden_row_cnt == opt_mode_size) {
         sizer->ShowItems(false);
         return false;
     }