diff --git a/imgui.cpp b/imgui.cpp
index cbd9a3a18..83470b3ee 100644
--- a/imgui.cpp
+++ b/imgui.cpp
@@ -7754,7 +7754,7 @@ static bool ImGui::GetWindowAlwaysWantOwnViewport(ImGuiWindow* window)
     ImGuiContext& g = *GImGui;
     if (g.IO.ConfigViewportsNoAutoMerge && (g.ConfigFlagsForFrame & ImGuiConfigFlags_ViewportsEnable))
         if (!window->DockIsActive)
-            if ((window->Flags & (ImGuiWindowFlags_ChildWindow | ImGuiWindowFlags_ChildMenu | ImGuiWindowFlags_Tooltip)) == 0)
+            if ((window->Flags & (ImGuiWindowFlags_ChildWindow | ImGuiWindowFlags_ChildMenu | ImGuiWindowFlags_Tooltip | ImGuiWindowFlags_Popup)) == 0)
                 return true;
     return false;
 }