diff --git a/imgui.cpp b/imgui.cpp
index fb64063d..0e20ca63 100644
--- a/imgui.cpp
+++ b/imgui.cpp
@@ -5083,13 +5083,14 @@ bool ImGui::SmallButton(const char* label)
 
 // Tip: use ImGui::PushID()/PopID() to push indices or pointers in the ID stack.
 // Then you can keep 'str_id' empty or the same for all your buttons (instead of creating a string based on a non-string id)
-bool ImGui::InvisibleButton(const char* str_id, const ImVec2& size)
+bool ImGui::InvisibleButton(const char* str_id, const ImVec2& size_arg)
 {
     ImGuiWindow* window = GetCurrentWindow();
     if (window->SkipItems)
         return false;
 
     const ImGuiID id = window->GetID(str_id);
+    ImVec2 size = CalcItemSize(size_arg, 0.0f, 0.0f);
     const ImRect bb(window->DC.CursorPos, window->DC.CursorPos + size);
     ItemSize(bb);
     if (!ItemAdd(bb, &id))