diff --git a/imgui.cpp b/imgui.cpp
index 0e401332..efc322aa 100644
--- a/imgui.cpp
+++ b/imgui.cpp
@@ -5097,9 +5097,10 @@ static ImGuiWindow* CreateNewWindow(const char* name, ImGuiWindowFlags flags)
     return window;
 }
 
-static ImVec2 CalcWindowSizeAfterConstraint(ImGuiWindow* window, ImVec2 new_size)
+static ImVec2 CalcWindowSizeAfterConstraint(ImGuiWindow* window, const ImVec2& size_desired)
 {
     ImGuiContext& g = *GImGui;
+    ImVec2 new_size = size_desired;
     if (g.NextWindowData.Flags & ImGuiNextWindowDataFlags_HasSizeConstraint)
     {
         // Using -1,-1 on either X/Y axis to preserve the current size.