diff --git a/src/slic3r/GUI/GLCanvas3D.cpp b/src/slic3r/GUI/GLCanvas3D.cpp
index 351929fd4..7924eea7a 100644
--- a/src/slic3r/GUI/GLCanvas3D.cpp
+++ b/src/slic3r/GUI/GLCanvas3D.cpp
@@ -3000,6 +3000,7 @@ void GLCanvas3D::on_mouse(wxMouseEvent& evt)
                 case GLGizmosManager::EType::Scale:
                 case GLGizmosManager::EType::Rotate:
                     update_sequential_clearance();
+                default: break;
                 }
             } else {
                 switch (m_gizmos.get_current_type()) {
@@ -3007,6 +3008,7 @@ void GLCanvas3D::on_mouse(wxMouseEvent& evt)
                 case GLGizmosManager::EType::Scale:
                 case GLGizmosManager::EType::Rotate: 
                     show_sinking_contours();
+                default: break;
                 }
             }
         }
diff --git a/src/slic3r/GUI/Gizmos/GLGizmoBase.cpp b/src/slic3r/GUI/Gizmos/GLGizmoBase.cpp
index 087b7229d..673028a01 100644
--- a/src/slic3r/GUI/Gizmos/GLGizmoBase.cpp
+++ b/src/slic3r/GUI/Gizmos/GLGizmoBase.cpp
@@ -178,7 +178,7 @@ bool GLGizmoBase::use_grabbers(const wxMouseEvent &mouse_event) {
 
             m_dragging = true;
             for (auto &grabber : m_grabbers) grabber.dragging = false;
-            if (!m_grabbers.empty() && m_hover_id < m_grabbers.size())
+            if (!m_grabbers.empty() && m_hover_id < int(m_grabbers.size()))
                 m_grabbers[m_hover_id].dragging = true;            
             
             // prevent change of hover_id during dragging
diff --git a/src/slic3r/GUI/Gizmos/GLGizmoBase.hpp b/src/slic3r/GUI/Gizmos/GLGizmoBase.hpp
index 8525086f7..3f1423ed3 100644
--- a/src/slic3r/GUI/Gizmos/GLGizmoBase.hpp
+++ b/src/slic3r/GUI/Gizmos/GLGizmoBase.hpp
@@ -9,6 +9,7 @@
 #include <cereal/archives/binary.hpp>
 
 class wxWindow;
+class wxMouseEvent;
 
 namespace Slic3r {