diff --git a/rpcs3/rpcs3qt/memory_viewer_panel.cpp b/rpcs3/rpcs3qt/memory_viewer_panel.cpp
index 9e9815385b..40b307e393 100644
--- a/rpcs3/rpcs3qt/memory_viewer_panel.cpp
+++ b/rpcs3/rpcs3qt/memory_viewer_panel.cpp
@@ -604,7 +604,7 @@ memory_viewer_panel::memory_viewer_panel(QWidget* parent, std::shared_ptr<CPUDis
 	{
 		if (auto fxo = g_fxo->try_get<memory_viewer_fxo>())
 		{
-			if (this == fxo->last_opened[m_type])
+			if (this == fxo->last_opened.at(m_type))
 				fxo->last_opened.erase(m_type);
 		}
 	});