diff --git a/sys/sys/dtrace_bsd.h b/sys/sys/dtrace_bsd.h
index fa54d7ed040a..7d63de9c1a18 100644
--- a/sys/sys/dtrace_bsd.h
+++ b/sys/sys/dtrace_bsd.h
@@ -38,8 +38,6 @@ struct thread;
 struct vattr;
 struct vnode;
 struct reg;
-struct devstat;
-struct bio;
 
 /*
  * Cyclic clock function type definition used to hook the cyclic
@@ -168,23 +166,6 @@ extern dtrace_nfsclient_nfs23_done_probe_func_t
 extern dtrace_nfsclient_nfs23_done_probe_func_t
     dtrace_nfscl_nfs234_done_probe;
 
-/* IO Provider hooks, really hook into devstat */
-typedef void (*dtrace_io_start_probe_func_t)(uint32_t, struct bio *,
-					     struct devstat *);
-extern dtrace_io_start_probe_func_t dtrace_io_start_probe;
-
-typedef void (*dtrace_io_done_probe_func_t)(uint32_t, struct bio *,
-					    struct devstat *);
-extern dtrace_io_done_probe_func_t dtrace_io_done_probe;
-
-typedef void (*dtrace_io_wait_start_probe_func_t)(uint32_t, uintptr_t *, 
-						  struct devstat *);
-extern dtrace_io_wait_start_probe_func_t dtrace_io_wait_start_probe;
-
-typedef void (*dtrace_io_wait_done_probe_func_t)(uint32_t, uintptr_t *, 
-						 struct devstat *);
-extern dtrace_io_wait_done_probe_func_t dtrace_io_wait_done_probe;
-
 /*
  * Functions which allow the dtrace module to check that the kernel 
  * hooks have been compiled with sufficient space for it's private