diff --git a/Memola/Canvas/RenderPasses/EraserRenderPass.swift b/Memola/Canvas/RenderPasses/EraserRenderPass.swift
index 32f115d..5290357 100644
--- a/Memola/Canvas/RenderPasses/EraserRenderPass.swift
+++ b/Memola/Canvas/RenderPasses/EraserRenderPass.swift
@@ -57,7 +57,7 @@ class EraserRenderPass: RenderPass {
         let quadCount = stroke.quads.endIndex
         var quads = stroke.quads
         let quadBuffer = renderer.device.makeBuffer(bytes: &quads, length: MemoryLayout<Quad>.stride * quadCount, options: [])
-        let indexBuffer = renderer.device.makeBuffer(length: MemoryLayout<UInt32>.stride * quadCount * 6, options: [])
+        let indexBuffer = renderer.device.makeBuffer(length: MemoryLayout<UInt>.stride * quadCount * 6, options: [])
         let vertexBuffer = renderer.device.makeBuffer(length: MemoryLayout<QuadVertex>.stride * quadCount * 4, options: [])
 
         computeEncoder.setComputePipelineState(quadPipelineState)
diff --git a/Memola/Canvas/RenderPasses/StrokeRenderPass.swift b/Memola/Canvas/RenderPasses/StrokeRenderPass.swift
index 89945af..a9a4887 100644
--- a/Memola/Canvas/RenderPasses/StrokeRenderPass.swift
+++ b/Memola/Canvas/RenderPasses/StrokeRenderPass.swift
@@ -70,7 +70,7 @@ class StrokeRenderPass: RenderPass {
         let quadCount = stroke.quads.endIndex
         var quads = stroke.quads
         let quadBuffer = renderer.device.makeBuffer(bytes: &quads, length: MemoryLayout<Quad>.stride * quadCount, options: [])
-        let indexBuffer = renderer.device.makeBuffer(length: MemoryLayout<UInt32>.stride * quadCount * 6, options: [])
+        let indexBuffer = renderer.device.makeBuffer(length: MemoryLayout<UInt>.stride * quadCount * 6, options: [])
         let vertexBuffer = renderer.device.makeBuffer(length: MemoryLayout<QuadVertex>.stride * quadCount * 4, options: [])
 
         computeEncoder.setComputePipelineState(quadPipelineState)
diff --git a/Memola/Canvas/Shaders/Quad.metal b/Memola/Canvas/Shaders/Quad.metal
index 898c3d0..6f2d7c3 100644
--- a/Memola/Canvas/Shaders/Quad.metal
+++ b/Memola/Canvas/Shaders/Quad.metal
@@ -38,7 +38,7 @@ Vertex createVertex(Quad quad, float2 factor, float2 textCoord) {
 }
 
 kernel void generate_stroke_vertices(
-    device Quad *quads [[buffer(0)]],
+    constant Quad *quads [[buffer(0)]],
     device uint *indices [[buffer(1)]],
     device Vertex *vertices [[buffer(2)]],
     uint gid [[thread_position_in_grid]]