diff --git a/mods/cubyz/rotation/branch.zig b/mods/cubyz/rotation/branch.zig
index e570bd5e..6461d466 100644
--- a/mods/cubyz/rotation/branch.zig
+++ b/mods/cubyz/rotation/branch.zig
@@ -289,7 +289,7 @@ pub fn createBlockModel(_: Block, modeData: *u16, zon: ZonElement) ModelIndex {
 			}
 		}
 
-		const index = main.models.Model.init(quads.items);
+		const index = main.models.Model.init(quads.items, null);
 		if(i == 0) {
 			modelIndex = index;
 		}
diff --git a/mods/cubyz/rotation/log.zig b/mods/cubyz/rotation/log.zig
index b82d4e5b..f18d9533 100644
--- a/mods/cubyz/rotation/log.zig
+++ b/mods/cubyz/rotation/log.zig
@@ -169,7 +169,7 @@ pub fn createBlockModel(_: Block, _: *u16, _: ZonElement) ModelIndex {
 			quads.append(rotateQuad(pattern, neighbor));
 		}
 
-		const index = main.models.Model.init(quads.items);
+		const index = main.models.Model.init(quads.items, null);
 		if(i == 0) {
 			modelIndex = index;
 		}
diff --git a/mods/cubyz/rotation/ore.zig b/mods/cubyz/rotation/ore.zig
index 56435a9b..6ad761c7 100644
--- a/mods/cubyz/rotation/ore.zig
+++ b/mods/cubyz/rotation/ore.zig
@@ -40,7 +40,7 @@ pub fn createBlockModel(_: Block, _: *u16, zon: ZonElement) ModelIndex {
 		quadList.items[i + len].textureSlot += 16;
 		quadList.items[i].opaqueInLod = 2;
 	}
-	const modelIndex = main.models.Model.init(quadList.items);
+	const modelIndex = main.models.Model.init(quadList.items, null);
 	modelCache = modelIndex;
 	return modelIndex;
 }
diff --git a/mods/cubyz/rotation/stairs.zig b/mods/cubyz/rotation/stairs.zig
index 9cf84737..c16732a4 100644
--- a/mods/cubyz/rotation/stairs.zig
+++ b/mods/cubyz/rotation/stairs.zig
@@ -14,7 +14,9 @@ const Mat4f = vec.Mat4f;
 const Vec2f = vec.Vec2f;
 const Vec3f = vec.Vec3f;
 const Vec3i = vec.Vec3i;
+const Vec3d = vec.Vec3d;
 const ZonElement = main.ZonElement;
+const AABB = main.game.collision.AABB;
 
 var modelIndex: ?ModelIndex = null;
 
@@ -234,7 +236,26 @@ pub fn createBlockModel(_: Block, _: *u16, _: ZonElement) ModelIndex {
 				});
 			}
 		}
-		const index = main.models.Model.init(quads.items);
+		var collision = main.globalAllocator.alloc(AABB, 8);
+		var hasBrokenParts = false;
+		for(0..8) |j| {
+			const x: u1 = @intCast(j & 0b001);
+			const y: u1 = @intCast((j & 0b010) >> 1);
+			const z: u1 = @intCast((j & 0b100) >> 2);
+			if(hasSubBlock(@intCast(i), x, y, z)) {
+				const minX = @as(f64, @floatFromInt(x)) * 0.5;
+				const minY = @as(f64, @floatFromInt(y)) * 0.5;
+				const minZ = @as(f64, @floatFromInt(z)) * 0.5;
+				const maxX = minX + 0.5;
+				const maxY = minY + 0.5;
+				const maxZ = minZ + 0.5;
+
+				collision[j] = AABB {.min = Vec3d{minX, minY, minZ}, .max = Vec3d{maxX, maxY, maxZ}};
+			} else {
+				hasBrokenParts = true;
+			}
+		}
+		const index = main.models.Model.init(quads.items, if(hasBrokenParts) collision else null);
 		if(i == 0) {
 			modelIndex = index;
 		}
diff --git a/src/models.zig b/src/models.zig
index f4e6bc81..323d89ba 100644
--- a/src/models.zig
+++ b/src/models.zig
@@ -124,7 +124,7 @@ pub const Model = struct {
 		return @popCount(@as(u3, @bitCast(hasTwoOnes))) == 2 and @popCount(@as(u3, @bitCast(hasTwoZeroes))) == 2;
 	}
 
-	pub fn init(quadInfos: []const QuadInfo) ModelIndex {
+	pub fn init(quadInfos: []const QuadInfo, collision: ?[]AABB) ModelIndex {
 		const adjustedQuads = main.stackAllocator.alloc(QuadInfo, quadInfos.len);
 		defer main.stackAllocator.free(adjustedQuads);
 		for(adjustedQuads, quadInfos) |*dest, *src| {
@@ -197,8 +197,12 @@ pub const Model = struct {
 			self.allNeighborsOccluded = self.allNeighborsOccluded and self.isNeighborOccluded[neighbor];
 			self.noNeighborsOccluded = self.noNeighborsOccluded and !self.isNeighborOccluded[neighbor];
 		}
-		self.collision = main.globalAllocator.alloc(AABB, 1);
-		self.collision[0] = AABB {.min = @floatCast(self.min), .max = @floatCast(self.max)};
+		if(collision)|realCollision| {
+			self.collision = realCollision;
+		} else {
+			self.collision = main.globalAllocator.alloc(AABB, 1);
+			self.collision[0] = AABB {.min = @floatCast(self.min), .max = @floatCast(self.max)};
+		}
 
 		return modelIndex;
 	}
@@ -235,7 +239,7 @@ pub const Model = struct {
 				quad.cornerUV[i] = @as(Vec2f, quad.cornerUV[i]) - minUv;
 			}
 		}
-		return Model.init(quadInfos);
+		return Model.init(quadInfos, null);
 	}
 
 	pub fn loadRawModelDataFromObj(allocator: main.heap.NeverFailingAllocator, data: []const u8) []QuadInfo {
@@ -415,7 +419,7 @@ pub const Model = struct {
 		for(modelList) |model| {
 			model.model().getRawFaces(&quadList);
 		}
-		return Model.init(quadList.items);
+		return Model.init(quadList.items, null);
 	}
 
 	pub fn transformModel(model: Model, transformFunction: anytype, transformFunctionParameters: anytype) ModelIndex {
@@ -425,7 +429,7 @@ pub const Model = struct {
 		for(quadList.items) |*quad| {
 			@call(.auto, transformFunction, .{quad} ++ transformFunctionParameters);
 		}
-		return Model.init(quadList.items);
+		return Model.init(quadList.items, null);
 	}
 
 	fn appendQuadsToList(quadList: []const QuadIndex, list: *main.ListUnmanaged(FaceData), allocator: NeverFailingAllocator, block: main.blocks.Block, x: i32, y: i32, z: i32, comptime backFace: bool) void {
@@ -581,7 +585,7 @@ pub fn init() void {
 
 	nameToIndex = .init(main.globalAllocator.allocator);
 
-	nameToIndex.put("none", Model.init(&.{})) catch unreachable;
+	nameToIndex.put("none", Model.init(&.{}, null)) catch unreachable;
 }
 
 pub fn reset() void {
@@ -593,7 +597,7 @@ pub fn reset() void {
 	extraQuadInfos.clearRetainingCapacity();
 	quadDeduplication.clearRetainingCapacity();
 	nameToIndex.clearRetainingCapacity();
-	nameToIndex.put("none", Model.init(&.{})) catch unreachable;
+	nameToIndex.put("none", Model.init(&.{}, null)) catch unreachable;
 }
 
 pub fn deinit() void {