diff --git a/tests/test_mixins.py b/tests/test_mixins.py
new file mode 100644
index 0000000..143e604
--- /dev/null
+++ b/tests/test_mixins.py
@@ -0,0 +1,40 @@
+import typing as tp
+from dataclasses import dataclass
+
+import jax
+import jax.numpy as jnp
+import numpy as np
+import pytest
+
+import treeo as to
+
+
+class TestMixins:
+    def test_apply(self):
+        @dataclass
+        class SomeTree(to.Tree, to.Apply):
+            x: int = to.node()
+
+        tree = SomeTree(x=1)
+
+        def f(tree: SomeTree):
+            tree.x = 2
+
+        tree2 = tree.apply(f)
+
+        assert tree.x == 1
+        assert tree2.x == 2
+
+    def test_apply_inplace(self):
+        @dataclass
+        class SomeTree(to.Tree, to.Apply):
+            x: int = to.node()
+
+        tree = SomeTree(x=1)
+
+        def f(tree: SomeTree):
+            tree.x = 2
+
+        tree.apply(f, inplace=True)
+
+        assert tree.x == 2
diff --git a/treeo/mixins.py b/treeo/mixins.py
index 5dc1cab..42e5fc4 100644
--- a/treeo/mixins.py
+++ b/treeo/mixins.py
@@ -219,7 +219,7 @@ def apply(self: A, f: tp.Callable[..., None], *rest: A, inplace: bool = False) -
         Returns:
             A new pytree with the updated Trees or the same input `obj` if `inplace` is `True`.
         """
-        return api.apply(f, self, *rest, inplace=inplace)
+        return tree_m.apply(f, self, *rest, inplace=inplace)
 
 
 class Compact:
diff --git a/treeo/tree.py b/treeo/tree.py
index 00af759..2453949 100644
--- a/treeo/tree.py
+++ b/treeo/tree.py
@@ -173,7 +173,8 @@ def __call__(cls, *args, **kwargs) -> "Tree":
             return obj
         else:
             obj = cls.__new__(cls)
-            obj = cls.construct(obj, *args, **kwargs)
+            with _make_mutable_single(obj):
+                obj = cls.construct(obj, *args, **kwargs)
 
         if _COMPACT_CONTEXT.new_subtrees is not None:
             _COMPACT_CONTEXT.new_subtrees.append(obj)
@@ -181,27 +182,27 @@ def __call__(cls, *args, **kwargs) -> "Tree":
         return obj
 
     def construct(cls, obj: T, *args, **kwargs) -> T:
-        with _make_mutable_single(obj):
-            obj._field_metadata = obj._field_metadata.copy()
 
-            # set default fields
-            for field, default_factory in obj._factory_fields.items():
-                setattr(obj, field, default_factory())
+        obj._field_metadata = obj._field_metadata.copy()
 
-            for field, default_value in obj._default_field_values.items():
-                setattr(obj, field, default_value)
+        # set default fields
+        for field, default_factory in obj._factory_fields.items():
+            setattr(obj, field, default_factory())
 
-            # reset context before __init__ and add obj as current tree
-            with _CompactContext(current_tree=obj):
-                obj.__init__(*args, **kwargs)
+        for field, default_value in obj._default_field_values.items():
+            setattr(obj, field, default_value)
 
-            # auto-annotations
-            obj._update_local_metadata()
+        # reset context before __init__ and add obj as current tree
+        with _CompactContext(current_tree=obj):
+            obj.__init__(*args, **kwargs)
 
-            if _COMPACT_CONTEXT.current_tree is not None:
-                obj._mutable = _COMPACT_CONTEXT.current_tree._mutable
+        # auto-annotations
+        obj._update_local_metadata()
 
-            return obj
+        if _COMPACT_CONTEXT.current_tree is not None:
+            obj._mutable = _COMPACT_CONTEXT.current_tree._mutable
+
+        return obj
 
 
 class Tree(metaclass=TreeMeta):