diff --git a/vulkan.d b/vulkan.d
index 4e9d27d..a93f1f7 100644
--- a/vulkan.d
+++ b/vulkan.d
@@ -1398,9 +1398,10 @@ Transfer(bool image, T)(Descriptor* desc, T data) if(isArray!(T) || isPointer!(T
 	}
 
   u64 copied = 0;
-  while(copied != data.length)
+  while(copied != data_length)
   {
-    u64 copy_length = transfer_length > (data_length - copied) ? data_length : transfer_length;
+		u64 remaining   = data_length-copied;
+    u64 copy_length = transfer_length > remaining ? remaining : transfer_length;
 
     g_vk.transfer_buf.data[0 .. copy_length] = data[copied .. copy_length];