diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9b20f3bc0..8412f0948 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -11,6 +11,8 @@ PLEASE REMEMBER TO CHANGE THE '..main' WITH AN ACTUAL TAG in GITHUB LINK.
 ## jax 0.2.28 (Unreleased)
 * [GitHub
   commits](https://github.com/google/jax/compare/jax-v0.2.27...main).
+  * `jax.jit(f).lower(...).compiler_ir()` now defaults to the MHLO dialect if no
+    `dialect=` is passed.
   * The `jax.jit(f).lower(...).compiler_ir(dialect='mhlo')` now returns an MLIR
     `ir.Module` object instead of its string representation.
 
diff --git a/jax/_src/api.py b/jax/_src/api.py
index 0a9901b96..e208c0410 100644
--- a/jax/_src/api.py
+++ b/jax/_src/api.py
@@ -522,9 +522,9 @@ class Lowered:
         self.donate_argnums, self._no_kwargs)
 
   def compiler_ir(self, dialect: Optional[str] = None):
-    if dialect == "mhlo":
+    if dialect is None or dialect == "mhlo":
       return self._lowering.mhlo()
-    elif dialect == "hlo" or dialect is None:
+    elif dialect == "hlo":
       return self._lowering.hlo()
     else:
       raise ValueError(f"Unknown dialect {dialect}")