diff --git a/testmaps/qbsp_q2_mirrorinside.map b/testmaps/qbsp_q2_mirrorinside.map
index d5491ebd..0cca2cf3 100644
--- a/testmaps/qbsp_q2_mirrorinside.map
+++ b/testmaps/qbsp_q2_mirrorinside.map
@@ -77,6 +77,15 @@
 ( 112 128 128 ) ( 113 128 128 ) ( 112 128 129 ) e1u1/brwater [ -1 0 0 0 ] [ 0 0 -1 0 ] 0 1 1 4 0 100
 ( 112 128 128 ) ( 112 128 129 ) ( 112 129 128 ) e1u1/brwater [ 0 1 0 32 ] [ 0 0 -1 0 ] 0 1 1 4 0 100
 }
+// brush 8
+{
+( 192 16 112 ) ( 192 17 112 ) ( 192 16 113 ) e2u2/wndow1_1 [ 0 -1 0 -32 ] [ 0 0 -1 0 ] 0 1 1 2 16 100
+( 144 64 112 ) ( 144 64 113 ) ( 145 64 112 ) e2u2/wndow1_1 [ 1 0 0 -48 ] [ 0 0 -1 0 ] 0 1 1 2 16 100
+( 144 16 112 ) ( 145 16 112 ) ( 144 17 112 ) e2u2/wndow1_1 [ -1 0 0 48 ] [ 0 -1 0 -32 ] 0 1 1 2 16 100
+( 224 128 192 ) ( 224 129 192 ) ( 225 128 192 ) e2u2/wndow1_1 [ 1 0 0 -48 ] [ 0 -1 0 -32 ] 0 1 1 2 16 100
+( 224 128 128 ) ( 225 128 128 ) ( 224 128 129 ) e2u2/wndow1_1 [ -1 0 0 48 ] [ 0 0 -1 0 ] 0 1 1 2 16 100
+( 224 128 128 ) ( 224 128 129 ) ( 224 129 128 ) e2u2/wndow1_1 [ 0 1 0 32 ] [ 0 0 -1 0 ] 0 1 1 2 16 100
+}
 }
 // entity 1
 {
diff --git a/tests/test_qbsp_q2.cc b/tests/test_qbsp_q2.cc
index 15051ad5..96782153 100644
--- a/tests/test_qbsp_q2.cc
+++ b/tests/test_qbsp_q2.cc
@@ -541,6 +541,13 @@ TEST_CASE("q2_mirrorinside" * doctest::test_suite("testmaps_q2"))
 {
     const auto [bsp, bspx, prt] = LoadTestmapQ2("qbsp_q2_mirrorinside.map");
 
+    {
+        INFO("window is not two sided by default");
+        const qvec3d window_pos{192, 96, 156};
+        CHECK_VECTORS_UNOREDERED_EQUAL(TexNames(bsp, BSP_FindFacesAtPoint(&bsp, &bsp.dmodels[0], window_pos)),
+            std::vector<std::string>({"e2u2/wndow1_1"}));
+    }
+
     {
         INFO("aux is not two sided by default");
         const qvec3d aux_pos{32, 96, 156};