diff --git a/ps1bsp.h b/ps1bsp.h
index 7b79a99..d9bd4c6 100755
--- a/ps1bsp.h
+++ b/ps1bsp.h
@@ -135,7 +135,6 @@ typedef struct
 	int planeId;
 	short children[2];
 
-	// TODO: add bounding box for frustum culling (or bounding sphere, might be cheaper)
 	SVECTOR boundingSphere;
 } ps1bsp_node_t;
 
@@ -144,8 +143,7 @@ typedef struct
 	int type;
 	int vislist;
 
-	// TODO: add bounding box for frustum culling (or do we? could save half the number of bounds checks if we only check nodes)
-	//SVECTOR center;
+	SVECTOR boundingSphere;
 
 	u_short firstLeafFace;
 	u_short numLeafFaces;
diff --git a/test.ps1bsp b/test.ps1bsp
index a78b035..60d25db 100755
Binary files a/test.ps1bsp and b/test.ps1bsp differ
diff --git a/world.c b/world.c
index ab179ca..8865ba0 100644
--- a/world.c
+++ b/world.c
@@ -193,8 +193,11 @@ static void world_drawnode(const world_t *world, short nodeIdx, u_char *pvs)
         if ((pvs[test >> 3] & (1 << (test & 0x7))) == 0)
             return;
 
-        u_long frameNum = time_getFrameNumber();
         const ps1bsp_leaf_t *leaf = &world->leaves[~nodeIdx];
+        // if (!frustum_sphereInside(&leaf->boundingSphere))    // TODO: not sure if it's actually faster to do all these additional frustum checks
+        //     return;
+
+        u_long frameNum = time_getFrameNumber();
         const u_short *leafFace = &world->leafFaces[leaf->firstLeafFace];
 
         for (u_short leafFaceIdx = 0; leafFaceIdx < leaf->numLeafFaces; ++leafFaceIdx, ++leafFace)