diff --git a/diffrax/_progress_meter.py b/diffrax/_progress_meter.py
index 8ad0acaf..dc792101 100644
--- a/diffrax/_progress_meter.py
+++ b/diffrax/_progress_meter.py
@@ -291,11 +291,14 @@ def _step(_progress, _idx):
                 except KeyError:
                     pass  # E.g. the backward pass after a forward pass.
                 else:
-                    step_bar(bar, _progress)
+                    # As above, `_idx` may have a spurious batch tracer. Correspondingly
+                    # `_progress` may pick up spurious length-1 batch dimensions from
+                    # `vmap_method="expand_dims"` below. Remove them now.
+                    step_bar(bar, np.array(_progress).reshape(()))
                 # Return the idx to thread the callbacks in the correct order.
                 return _idx
 
-        return jax.pure_callback(_step, idx, progress, idx, vectorized=True)
+        return jax.pure_callback(_step, idx, progress, idx, vmap_method="expand_dims")
 
     def close(self, close_bar: Callable[[Any], None], idx: IntScalarLike):
         def _close(_idx):
diff --git a/pyproject.toml b/pyproject.toml
index be5520e7..62055140 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -23,7 +23,7 @@ classifiers = [
     "Topic :: Scientific/Engineering :: Mathematics",
 ]
 urls = {repository = "https://github.com/patrick-kidger/diffrax" }
-dependencies = ["jax>=0.4.28", "jaxtyping>=0.2.24", "typing_extensions>=4.5.0", "typeguard==2.13.3", "equinox>=0.11.10", "lineax>=0.0.5", "optimistix>=0.0.7"]
+dependencies = ["jax>=0.4.38", "jaxtyping>=0.2.24", "typing_extensions>=4.5.0", "typeguard==2.13.3", "equinox>=0.11.10", "lineax>=0.0.5", "optimistix>=0.0.7"]
 
 [build-system]
 requires = ["hatchling"]