diff --git a/imgui.cpp b/imgui.cpp
index 5f5a80a79..a98806171 100644
--- a/imgui.cpp
+++ b/imgui.cpp
@@ -4245,10 +4245,10 @@ bool ImGui::Begin(const char* name, bool* p_open, ImGuiWindowFlags flags)
         // Update scrollbar status based on the Size that was effective during last frame (and not the upcoming Size which we are updating below), so that user code consuming exactly the available size won't trigger scrollbars when e.g. manually resizing.
         if (!window->Collapsed)
         {
-            window->ScrollbarY = (flags & ImGuiWindowFlags_AlwaysVerticalScrollbar) || ((window->SizeContents.y > window->Size.y + style.ItemSpacing.y) && !(flags & ImGuiWindowFlags_NoScrollbar));
-            window->ScrollbarX = (flags & ImGuiWindowFlags_AlwaysHorizontalScrollbar) || ((window->SizeContents.x > window->Size.x - (window->ScrollbarY ? style.ScrollbarSize : 0.0f) - window->WindowPadding.x) && !(flags & ImGuiWindowFlags_NoScrollbar) && (flags & ImGuiWindowFlags_HorizontalScrollbar));
+            window->ScrollbarY = (flags & ImGuiWindowFlags_AlwaysVerticalScrollbar) || ((window->SizeContents.y > window->SizeFull.y + style.ItemSpacing.y) && !(flags & ImGuiWindowFlags_NoScrollbar));
+            window->ScrollbarX = (flags & ImGuiWindowFlags_AlwaysHorizontalScrollbar) || ((window->SizeContents.x > window->SizeFull.x - (window->ScrollbarY ? style.ScrollbarSize : 0.0f) - window->WindowPadding.x) && !(flags & ImGuiWindowFlags_NoScrollbar) && (flags & ImGuiWindowFlags_HorizontalScrollbar));
             if (window->ScrollbarX && !window->ScrollbarY)
-                window->ScrollbarY = (window->SizeContents.y > window->Size.y + style.ItemSpacing.y - style.ScrollbarSize) && !(flags & ImGuiWindowFlags_NoScrollbar);
+                window->ScrollbarY = (window->SizeContents.y > window->SizeFull.y + style.ItemSpacing.y - style.ScrollbarSize) && !(flags & ImGuiWindowFlags_NoScrollbar);
             window->ScrollbarSizes = ImVec2(window->ScrollbarY ? style.ScrollbarSize : 0.0f, window->ScrollbarX ? style.ScrollbarSize : 0.0f);
             window->BorderSize = (flags & ImGuiWindowFlags_ShowBorders) ? 1.0f : 0.0f;
         }