diff --git a/source/MRViewer/MRRibbonMenu.cpp b/source/MRViewer/MRRibbonMenu.cpp
index cf652d652058..135b5f91a596 100644
--- a/source/MRViewer/MRRibbonMenu.cpp
+++ b/source/MRViewer/MRRibbonMenu.cpp
@@ -2383,20 +2383,33 @@ void RibbonMenu::endTopPanel_()
     ImGui::PopStyleVar( 3 );
 }
 
-void RibbonMenu::drawTopPanel_( bool drawTabs, bool centerItems )
+void RibbonMenu::updateTopPanelSize_( bool drawTabs )
 {
+    constexpr int cTabSize = int( cTabHeight + cTabYOffset + 1 );
+    constexpr int cSumPanelSizeSize = cTabSize + 80;
+    if ( drawTabs && topPanelHiddenHeight_ == cTabSize )
+        return;
+    if ( !drawTabs && topPanelHiddenHeight_ == 0 )
+        return;
     if ( drawTabs )
     {
-        currentTopPanelHeight_ = 113;
-        topPanelOpenedHeight_ = 113;
-        topPanelHiddenHeight_ = 33;
+        topPanelOpenedHeight_ = cSumPanelSizeSize;
+        topPanelHiddenHeight_ = cTabSize;
     }
     else
     {
-        currentTopPanelHeight_ = 113 - 33;
-        topPanelOpenedHeight_ = 113 - 33;
-        topPanelHiddenHeight_ = 33 - 33;
+        topPanelOpenedHeight_ = cSumPanelSizeSize - cTabSize;
+        topPanelHiddenHeight_ = 0;
+        collapseState_ = CollapseState::Pinned;
     }
+    currentTopPanelHeight_ = collapseState_ == CollapseState::Closed ? topPanelHiddenHeight_ : topPanelOpenedHeight_;
+
+    fixViewportsSize_( getViewerInstance().framebufferSize.x, getViewerInstance().framebufferSize.y );
+}
+
+void RibbonMenu::drawTopPanel_( bool drawTabs, bool centerItems )
+{
+    updateTopPanelSize_( drawTabs );
 
     switch ( collapseState_ )
     {
diff --git a/source/MRViewer/MRRibbonMenu.h b/source/MRViewer/MRRibbonMenu.h
index aaf4ffee4df7..2897b0510d11 100644
--- a/source/MRViewer/MRRibbonMenu.h
+++ b/source/MRViewer/MRRibbonMenu.h
@@ -228,6 +228,9 @@ class MRVIEWER_CLASS RibbonMenu : public ImGuiMenu
     // call this to draw RibbonNotifier with respect of scene size and ribbon top panel
     MRVIEWER_API virtual void drawNotifications_();
 
+    // this function changes internal sizes of topPanel when it is enabled or disabled
+    MRVIEWER_API virtual void updateTopPanelSize_( bool drawTabs );
+
     RibbonLayoutMode layoutMode_{ RibbonLayoutMode::All };
 
     RibbonMenuSearch searcher_;