diff --git a/src/Memory.hs b/src/Memory.hs
index be94627..0a4ea13 100644
--- a/src/Memory.hs
+++ b/src/Memory.hs
@@ -21,10 +21,10 @@ initAllocator
   -> Vk.Instance
   -> m VMA.Allocator
 initAllocator physicalDevice device instance' = do
-  instanceProcAddr <- liftIO $ peek $ castFunPtrToPtr $
-    Vk.pVkGetInstanceProcAddr ((Vk.instanceCmds :: Vk.Instance -> Vk.InstanceCmds) instance')
-  deviceProcAddr <- liftIO $ peek $ castFunPtrToPtr $
-    Vk.pVkGetDeviceProcAddr ((Vk.deviceCmds :: Vk.Device -> Vk.DeviceCmds) device)
+  let instanceProcAddr = castFunPtr $
+        Vk.pVkGetInstanceProcAddr ((Vk.instanceCmds :: Vk.Instance -> Vk.InstanceCmds) instance')
+      deviceProcAddr = castFunPtr $
+        Vk.pVkGetDeviceProcAddr ((Vk.deviceCmds :: Vk.Device -> Vk.DeviceCmds) device)
   let allocatorInfo = Vk.zero
         { VMA.physicalDevice  = Vk.physicalDeviceHandle physicalDevice
         , VMA.device          = Vk.deviceHandle device
diff --git a/src/Mesh.hs b/src/Mesh.hs
index 3d294f1..e89c2ee 100644
--- a/src/Mesh.hs
+++ b/src/Mesh.hs
@@ -10,7 +10,7 @@ import qualified Data.Vector as V
 
 import Foreign
 
-import Linear (V3(..))
+import Linear (V3(..), V4(..))
 
 import qualified VulkanMemoryAllocator as VMA
 import qualified Vulkan.Core10 as Vk
@@ -24,9 +24,9 @@ loadMeshes
   :: V.Vector Vertex
 loadMeshes =
   V.fromList
-    [ Vertex (V3 0.5 0.5 0)    (V3 0 1 0) undefined
-    , Vertex (V3 (-0.5) 0.5 0) (V3 0 1 0) undefined
-    , Vertex (V3 0 (-0.5) 0)   (V3 0 1 0) undefined
+    [ Vertex (V3 0.5 0.5 0)    (V3 0 1 0) (V4 0 0 0 0)
+    , Vertex (V3 (-0.5) 0.5 0) (V3 0 1 0) (V4 0 0 0 0)
+    , Vertex (V3 0 (-0.5) 0)   (V3 0 1 0) (V4 0 0 0 0)
     ]
 
 uploadMesh
@@ -36,7 +36,7 @@ uploadMesh
   -> m Mesh
 uploadMesh vertices allocator = do
   let bufferCreateInfo = Vk.zero
-        { Vk.size  = fromIntegral $ sizeOf (undefined :: Vertex)
+        { Vk.size  = fromIntegral $ sizeOf (Vertex (V3 0 0 0) (V3 0 0 0 ) (V4 0 0 0 0))
         , Vk.usage = Vk.BUFFER_USAGE_VERTEX_BUFFER_BIT
         }
       allocationCreateInfo = Vk.zero