diff --git a/src/main.cpp b/src/main.cpp
index e69ada5..9838f0a 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -1,6 +1,7 @@
 #include "globals.hpp"
 
 #include <GLES3/gl32.h>
+#include <any>
 #include <cmath>
 #include <hyprgraphics/color/Color.hpp>
 // version.hpp will be generated by meson
@@ -285,12 +286,16 @@ class CRenderWobblyWindowPassElement final: public IPassElement {
     PHLWINDOWREF m_pWindow;
 };
 
-// TODO: unregister on close
 void registerWindow(PHLWINDOW pWindow) {
     g_windowPositions[pWindow] = pWindow->m_realPosition->value();
 }
 
+void unregisterWindow(PHLWINDOW pWindow) {
+    g_windowPositions.erase(PHLWINDOWREF {pWindow});
+}
+
 static SP<HOOK_CALLBACK_FN> g_openWindow = nullptr;
+static SP<HOOK_CALLBACK_FN> g_closeWindow = nullptr;
 inline CFunctionHook* g_pRenderWindowHook = nullptr;
 
 typedef void (*origRenderWindow)(
@@ -518,6 +523,14 @@ APICALL EXPORT PLUGIN_DESCRIPTION_INFO PLUGIN_INIT(HANDLE handle) {
         }
     );
 
+    g_closeWindow = HyprlandAPI::registerCallbackDynamic(
+        PHANDLE,
+        "closeWindow",
+        [](void* self, SCallbackInfo& info, std::any data) {
+            unregisterWindow(std::any_cast<PHLWINDOW>(data));
+        }
+    );
+
     static const auto METHODS = HyprlandAPI::findFunctionsByName(PHANDLE, "renderWindow");
     g_pRenderWindowHook =
         HyprlandAPI::createFunctionHook(handle, METHODS[0].address, (void*)&hkRenderWindow);