diff --git a/include/qbsp/qbsp.hh b/include/qbsp/qbsp.hh
index 935d2c5b..65d0f004 100644
--- a/include/qbsp/qbsp.hh
+++ b/include/qbsp/qbsp.hh
@@ -630,7 +630,10 @@ struct node_t
     bool is_leaf = false;
 
     // information for decision nodes
-    qbsp_plane_t plane; // decision node only
+    size_t planenum; // decision node only
+
+    const qbsp_plane_t &get_plane() const;
+
     int firstface; // decision node only
     int numfaces; // decision node only
     twosided<std::unique_ptr<node_t>>
diff --git a/qbsp/brushbsp.cc b/qbsp/brushbsp.cc
index e68fe3a6..f52ceee1 100644
--- a/qbsp/brushbsp.cc
+++ b/qbsp/brushbsp.cc
@@ -621,10 +621,10 @@ static twosided<std::unique_ptr<bspbrush_t>> SplitBrush(std::unique_ptr<bspbrush
     return result;
 }
 
-static void CheckPlaneAgainstParents(const qbsp_plane_t &plane, node_t *node)
+inline void CheckPlaneAgainstParents(size_t planenum, node_t *node)
 {
     for (node_t *p = node->parent; p; p = p->parent) {
-        if (qv::epsilonEqual(p->plane, plane)) {
+        if (p->planenum == planenum) {
             Error("Tried parent");
         }
     }
@@ -875,9 +875,10 @@ static std::optional<size_t> SelectSplitPlane(const std::vector<std::unique_ptr<
                 if (side.visible ^ (pass < 2))
                     continue; // only check visible faces on first pass
 
+                size_t positive_planenum = side.planenum & ~1;
                 const qbsp_plane_t &plane = side.get_positive_plane(); // always use positive facing plane
 
-                CheckPlaneAgainstParents(plane, node);
+                CheckPlaneAgainstParents(positive_planenum, node);
 
                 if (!CheckPlaneAgainstVolume(plane, node, stats))
                     continue; // would produce a tiny volume
@@ -892,7 +893,7 @@ static std::optional<size_t> SelectSplitPlane(const std::vector<std::unique_ptr<
 
                 for (auto &test : brushes) {
                     int bsplits;
-                    int s = TestBrushToPlanenum(*test, side.planenum & ~1, &bsplits, &hintsplit, &epsilonbrush);
+                    int s = TestBrushToPlanenum(*test, positive_planenum, &bsplits, &hintsplit, &epsilonbrush);
 
                     splits += bsplits;
                     if (bsplits && (s & PSIDE_FACING))
@@ -1054,10 +1055,10 @@ static void BuildTree_r(node_t *node, std::vector<std::unique_ptr<bspbrush_t>> b
     // make sure this was a positive-facing split
     Q_assert(!(bestplane.value() & 1));
 
+    node->planenum = bestplane.value();
+    
     auto &plane = map.get_plane(bestplane.value());
-    node->plane.set_plane(plane);
-
-    auto children = SplitBrushList(std::move(brushes), node->plane, stats);
+    auto children = SplitBrushList(std::move(brushes), plane, stats);
 
     // allocate children before recursing
     for (int i = 0; i < 2; i++) {
@@ -1074,7 +1075,7 @@ static void BuildTree_r(node_t *node, std::vector<std::unique_ptr<bspbrush_t>> b
 		}
 	}
 
-    auto children_volumes = SplitBrush(node->volume->copy_unique(), node->plane, stats);
+    auto children_volumes = SplitBrush(node->volume->copy_unique(), plane, stats);
     node->children[0]->volume = std::move(children_volumes[0]);
     node->children[1]->volume = std::move(children_volumes[1]);
 
@@ -1135,9 +1136,9 @@ static std::unique_ptr<tree_t> BrushBSP(mapentity_t *entity, std::vector<std::un
          */
         auto headnode = std::make_unique<node_t>();
         headnode->bounds = entity->bounds;
-        // The choice of plane is mostly unimportant, but having it at (0, 0, 0) was affecting
-        // the node bounds calculation. So to be safe, put the plane on the top of the entity bounding box.
-        headnode->plane = {{0, 0, 1}, headnode->bounds.maxs()[2]};
+        // The choice of plane is mostly unimportant, but having it at (0, 0, 0) affects
+        // the node bounds calculation.
+        headnode->planenum = 0;
         headnode->children[0] = std::make_unique<node_t>();
         headnode->children[0]->is_leaf = true;
         headnode->children[0]->contents = qbsp_options.target_game->create_empty_contents();
diff --git a/qbsp/faces.cc b/qbsp/faces.cc
index 7c33f848..a65d1058 100644
--- a/qbsp/faces.cc
+++ b/qbsp/faces.cc
@@ -295,7 +295,7 @@ static void AddMarksurfaces_r(face_t *face, std::unique_ptr<face_t> face_copy, n
         return;
     }
 
-    const qplane3d &splitplane = node->plane;
+    const qplane3d &splitplane = node->get_plane();
 
     auto [frontFragment, backFragment] = SplitFace(std::move(face_copy), splitplane);
     if (frontFragment) {
@@ -479,7 +479,7 @@ static std::unique_ptr<face_t> FaceFromPortal(portal_t *p, bool pside)
     auto f = std::make_unique<face_t>();
 
     f->texinfo = side->texinfo;
-    f->planenum = (side->planenum & ~1) | pside;
+    f->planenum = (side->planenum & ~1) | (pside ? 1 : 0);
     f->portal = p;
     f->lmshift = side->lmshift;
 
diff --git a/qbsp/outside.cc b/qbsp/outside.cc
index a3289021..51fa5512 100644
--- a/qbsp/outside.cc
+++ b/qbsp/outside.cc
@@ -59,7 +59,7 @@ static node_t *PointInLeaf(node_t *node, const qvec3d &point)
         return node;
     }
 
-    vec_t dist = node->plane.distance_to(point);
+    vec_t dist = node->get_plane().distance_to(point);
 
     if (dist > 0) {
         // point is on the front of the node plane
diff --git a/qbsp/portals.cc b/qbsp/portals.cc
index f3da675d..82d8dd38 100644
--- a/qbsp/portals.cc
+++ b/qbsp/portals.cc
@@ -197,13 +197,13 @@ constexpr vec_t SPLIT_WINDING_EPSILON = 0.001;
 
 static std::optional<winding_t> BaseWindingForNode(const node_t *node)
 {
-    std::optional<winding_t> w = BaseWindingForPlane(node->plane);
+    std::optional<winding_t> w = BaseWindingForPlane(node->get_plane());
 
     // clip by all the parents
     for (auto *np = node->parent; np && w;) {
         const planeside_t keep = (np->children[0].get() == node) ? SIDE_FRONT : SIDE_BACK;
 
-        w = w->clip(np->plane, BASE_WINDING_EPSILON, false)[keep];
+        w = w->clip(np->get_plane(), BASE_WINDING_EPSILON, false)[keep];
 
         node = np;
         np = np->parent;
@@ -250,7 +250,7 @@ std::unique_ptr<buildportal_t> MakeNodePortal(node_t *node, const std::list<std:
     }
 
     auto new_portal = std::make_unique<buildportal_t>();
-    new_portal->plane = node->plane;
+    new_portal->plane = node->get_plane();
     new_portal->onnode = node;
     new_portal->winding = std::make_unique<winding_t>(*w);
     new_portal->set_nodes(node->children[0].get(), node->children[1].get());
@@ -268,7 +268,7 @@ children have portals instead of node.
 */
 twosided<std::list<std::unique_ptr<buildportal_t>>> SplitNodePortals(const node_t *node, std::list<std::unique_ptr<buildportal_t>> boundary_portals, portalstats_t &stats)
 {
-    const auto &plane = node->plane;
+    const auto &plane = node->get_plane();
     node_t *f = node->children[0].get();
     node_t *b = node->children[1].get();
 
@@ -791,7 +791,7 @@ static void FindPortalSide(portal_t *p)
     // bestside[0] is the brushside visible on portal side[0] which is the positive side of the plane, always
     side_t *bestside[2] = {nullptr, nullptr};
     float bestdot = 0;
-    const qbsp_plane_t &p1 = p->onnode->plane;
+    const qbsp_plane_t &p1 = p->onnode->get_plane();
 
     // check brushes on both sides of the portal
     for (int j = 0; j < 2; j++) {
@@ -816,7 +816,7 @@ static void FindPortalSide(portal_t *p)
                 // fixme-brushbsp: restore
                 //                if (!side.visible)
                 //                    continue;		// non-visible
-                if (qv::epsilonEqual(side.get_positive_plane(), p1)) {
+                if ((side.planenum & ~1) == p->onnode->planenum) {
                     // exact match (undirectional)
 
                     // because the brush is on j of the positive plane, the brushside must be facing away from j
diff --git a/qbsp/qbsp.cc b/qbsp/qbsp.cc
index 11c2fa87..b134a94b 100644
--- a/qbsp/qbsp.cc
+++ b/qbsp/qbsp.cc
@@ -56,6 +56,11 @@ const qbsp_plane_t &face_t::get_positive_plane() const
     return map.get_plane(planenum & ~1);
 }
 
+const qbsp_plane_t &node_t::get_plane() const
+{
+    return map.get_plane(planenum);
+}
+
 // command line flags
 namespace settings
 {
diff --git a/qbsp/writebsp.cc b/qbsp/writebsp.cc
index c6705d31..f1a3984b 100644
--- a/qbsp/writebsp.cc
+++ b/qbsp/writebsp.cc
@@ -153,7 +153,7 @@ static size_t ExportClipNodes(node_t *node)
 
     // Careful not to modify the vector while using this clipnode pointer
     bsp2_dclipnode_t &clipnode = map.bsp.dclipnodes[nodenum];
-    clipnode.planenum = ExportMapPlane(node->plane);
+    clipnode.planenum = ExportMapPlane(node->get_plane());
     clipnode.children[0] = child0;
     clipnode.children[1] = child1;
 
@@ -249,7 +249,7 @@ static void ExportDrawNodes(node_t *node)
     dnode->mins = qv::floor(node->bounds.mins());
     dnode->maxs = qv::ceil(node->bounds.maxs());
 
-    dnode->planenum = ExportMapPlane(node->plane);
+    dnode->planenum = ExportMapPlane(node->get_plane());
     dnode->firstface = node->firstface;
     dnode->numfaces = node->numfaces;