diff --git a/gpjax/scan.py b/gpjax/scan.py
index 4ca2eebf4..fcec3aba9 100644
--- a/gpjax/scan.py
+++ b/gpjax/scan.py
@@ -22,7 +22,6 @@
 )
 import jax
 from jax import lax
-from jax.experimental import host_callback as hcb
 import jax.numpy as jnp
 import jax.tree_util as jtu
 from jaxtyping import (
@@ -54,7 +53,8 @@ def _callback(cond: ScalarBool, func: Callable, *args: Any) -> None:
 
     def _do_callback(_) -> int:
         """Perform the callback."""
-        return hcb.id_tap(func, *args, result=_dummy_result)
+        jax.debug.callback(func, *args)
+        return _dummy_result
 
     def _not_callback(_) -> int:
         """Do nothing."""
@@ -113,19 +113,19 @@ def vscan(
     _progress_bar = trange(_length)
     _progress_bar.set_description("Compiling...", refresh=True)
 
-    def _set_running(args: Any, transform: Any) -> None:
+    def _set_running(*args: Any) -> None:
         """Set the tqdm progress bar to running."""
         _progress_bar.set_description("Running", refresh=False)
 
-    def _update_tqdm(args: Any, transform: Any) -> None:
+    def _update_tqdm(*args: Any) -> None:
         """Update the tqdm progress bar with the latest objective value."""
         _value, _iter_num = args
-        _progress_bar.update(_iter_num)
+        _progress_bar.update(_iter_num.item())
 
         if log_value and _value is not None:
             _progress_bar.set_postfix({"Value": f"{_value: .2f}"})
 
-    def _close_tqdm(args: Any, transform: Any) -> None:
+    def _close_tqdm(*args: Any) -> None:
         """Close the tqdm progress bar."""
         _progress_bar.close()
 
@@ -145,16 +145,16 @@ def _body_fun(carry: Carry, iter_num_and_x: Tuple[ScalarInt, X]) -> Tuple[Carry,
         _is_last: bool = iter_num == _length - 1
 
         # Update progress bar, if first of log_rate.
-        _callback(_is_first, _set_running, (y, log_rate))
+        _callback(_is_first, _set_running)
 
         # Update progress bar, if multiple of log_rate.
-        _callback(_is_multiple, _update_tqdm, (y, log_rate))
+        _callback(_is_multiple, _update_tqdm, y, log_rate)
 
         # Update progress bar, if remainder.
-        _callback(_is_remainder, _update_tqdm, (y, _remainder))
+        _callback(_is_remainder, _update_tqdm, y, _remainder)
 
         # Close progress bar, if last iteration.
-        _callback(_is_last, _close_tqdm, (y, None))
+        _callback(_is_last, _close_tqdm)
 
         return carry, y