diff --git a/src/slic3r/GUI/BBLTopbar.cpp b/src/slic3r/GUI/BBLTopbar.cpp
index 41dac2312..6fc4809c6 100644
--- a/src/slic3r/GUI/BBLTopbar.cpp
+++ b/src/slic3r/GUI/BBLTopbar.cpp
@@ -505,7 +505,13 @@ void BBLTopbar::OnFullScreen(wxAuiToolBarEvent& event)
     else {
         wxDisplay display(this);
         auto      size = display.GetClientArea().GetSize();
-        m_frame->SetMaxSize(size + wxSize{16, 16});
+#ifdef __WXMSW__
+        HWND hWnd = m_frame->GetHandle();
+        RECT      borderThickness;
+        SetRectEmpty(&borderThickness);
+        AdjustWindowRectEx(&borderThickness, GetWindowLongPtr(hWnd, GWL_STYLE), FALSE, 0);
+        m_frame->SetMaxSize(size + wxSize{-borderThickness.left + borderThickness.right, -borderThickness.top + borderThickness.bottom});
+#endif //  __WXMSW__
         m_normalRect = m_frame->GetRect();
         m_frame->Maximize();
     }
@@ -530,16 +536,8 @@ void BBLTopbar::OnMouseLeftDClock(wxMouseEvent& mouse)
     return;
 #endif //  __WXMSW__
 
-    if (m_frame->IsMaximized()) {
-        m_frame->Restore();
-    }
-    else {
-        wxDisplay display(this);
-        auto      size = display.GetClientArea().GetSize();
-        m_frame->SetMaxSize(size + wxSize{16, 16});
-        m_normalRect = m_frame->GetRect();
-        m_frame->Maximize();
-    }
+    wxAuiToolBarEvent evt;
+    OnFullScreen(evt);
 }
 
 void BBLTopbar::OnFileToolItem(wxAuiToolBarEvent& evt)
diff --git a/src/slic3r/GUI/MainFrame.cpp b/src/slic3r/GUI/MainFrame.cpp
index fe6e64cfd..4a313a15d 100644
--- a/src/slic3r/GUI/MainFrame.cpp
+++ b/src/slic3r/GUI/MainFrame.cpp
@@ -384,18 +384,27 @@ DPIFrame(NULL, wxID_ANY, "", wxDefaultPosition, wxDefaultSize, BORDERLESS_FRAME_
     auto setMaxSize = [this]() {
         wxDisplay display(this);
         auto size = display.GetClientArea().GetSize();
-        // 8 pixels shadow
-        SetMaxSize(size + wxSize{16, 16});
+        HWND      hWnd = GetHandle();
+        RECT      borderThickness;
+        SetRectEmpty(&borderThickness);
+        AdjustWindowRectEx(&borderThickness, GetWindowLongPtr(hWnd, GWL_STYLE), FALSE, 0);
+        SetMaxSize(size + wxSize{-borderThickness.left + borderThickness.right, -borderThickness.top + borderThickness.bottom});
     };
     this->Bind(wxEVT_DPI_CHANGED, [setMaxSize](auto & e) {
         setMaxSize();
         e.Skip();
         });
     setMaxSize();
+    // SetMaximize already position window at left/top corner, even if Windows Task Bar is at left side.
+    // Not known why, but fix it here
     this->Bind(wxEVT_MAXIMIZE, [this](auto &e) {
         wxDisplay display(this);
         auto pos = display.GetClientArea().GetPosition();
-        Move(pos - wxPoint{8, 8});
+        HWND      hWnd = GetHandle();
+        RECT      borderThickness;
+        SetRectEmpty(&borderThickness);
+        AdjustWindowRectEx(&borderThickness, GetWindowLongPtr(hWnd, GWL_STYLE), FALSE, 0);
+        Move(pos + wxPoint{borderThickness.left, borderThickness.top});
         e.Skip();
     });
 #endif // WIN32