diff --git a/.gitignore b/.gitignore
index 1e64e01..d86cd1b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,4 +1,5 @@
 .ruff_cache
+.vscode
 
 # Byte-compiled / optimized / DLL files
 __pycache__/
diff --git a/pyproject.toml b/pyproject.toml
index 496463e..10743c0 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -28,19 +28,14 @@ docs = ["pdoc"]
 styx = "styx.main:main"
 
 [tool.pytest.ini_options]
-pythonpath = [
-  "src"
-]
+pythonpath = ["src"]
 
 [tool.mypy]
 ignore_missing_imports = true
 
 [tool.ruff]
 preview = true
-extend-exclude = [
-  "examples",
-  "src/styx/boutiques/model.py"
-]
+extend-exclude = ["examples", "src/styx/boutiques/model.py"]
 line-length = 120
 indent-width = 4
 src = ["src"]
@@ -62,7 +57,9 @@ unfixable = []
 convention = "google"
 
 [tool.ruff.lint.per-file-ignores]
-"tests/**/*.py" = []
+"tests/**/*.py" = [
+  "ANN401"  # Dynamic type expression ('Any')
+]
 
 [build-system]
 requires = ["poetry-core>=1.2.0"]
diff --git a/src/styx/ir/pretty_print.py b/src/styx/ir/pretty_print.py
index 1194f2c..9030fcd 100644
--- a/src/styx/ir/pretty_print.py
+++ b/src/styx/ir/pretty_print.py
@@ -68,6 +68,17 @@ def field_is_default(obj: Any, field_: dataclasses.Field) -> bool:  # noqa: ANN4
                     ),
                     ")",
                 ])
+            if hasattr(obj, "__dict__"):
+                return f"\n{_indentation(ind)}".join([
+                    f"{obj.__class__.__name__}(",
+                    *_expand(
+                        ",\n".join([
+                            f" {field_name}={_pretty_print(field_value, 1)}"
+                            for field_name, field_value in obj.__dict__.items()
+                        ])
+                    ),
+                    ")",
+                ])
             else:
                 return str(obj)
 
diff --git a/tests/frontend/boutiques/test_command_line.py b/tests/frontend/boutiques/test_command_line.py
new file mode 100644
index 0000000..1dfbb0e
--- /dev/null
+++ b/tests/frontend/boutiques/test_command_line.py
@@ -0,0 +1,37 @@
+import styx.ir.core as ir
+from styx.frontend.boutiques.core import from_boutiques
+
+
+class TestCommandLine:
+    package_name = "My package"
+    descriptor_name = "My descriptor"
+
+    def test_basic(self) -> None:
+        bt = {
+            "name": self.descriptor_name,
+            "command-line": "hello world",
+        }
+        out = from_boutiques(bt, self.package_name)
+
+        assert isinstance(out.command.body, ir.Param.Struct)
+        groups = out.command.body.groups
+        assert len(groups) == 2
+        assert isinstance(groups[0].cargs[0].tokens[0], str)
+        assert groups[0].cargs[0].tokens[0] == "hello"
+        assert isinstance(groups[1].cargs[0].tokens[0], str)
+        assert groups[1].cargs[0].tokens[0] == "world"
+
+    def test_quoting(self) -> None:
+        bt = {
+            "name": self.descriptor_name,
+            "command-line": 'hello "string with whitespace"',
+        }
+        out = from_boutiques(bt, self.package_name)
+
+        assert isinstance(out.command.body, ir.Param.Struct)
+        groups = out.command.body.groups
+        assert len(groups) == 2
+        assert isinstance(groups[0].cargs[0].tokens[0], str)
+        assert groups[0].cargs[0].tokens[0] == "hello"
+        assert isinstance(groups[1].cargs[0].tokens[0], str)
+        assert groups[1].cargs[0].tokens[0] == "string with whitespace"
diff --git a/tests/frontend/boutiques/test_descriptor.py b/tests/frontend/boutiques/test_descriptor.py
new file mode 100644
index 0000000..f410935
--- /dev/null
+++ b/tests/frontend/boutiques/test_descriptor.py
@@ -0,0 +1,27 @@
+from typing import Any
+
+import pytest
+
+import styx.ir.core as ir
+from styx.frontend.boutiques.core import from_boutiques
+
+
+class TestDescriptor:
+    package_name = "My package"
+    descriptor_name = "My descriptor"
+
+    def test_descriptor(self) -> None:
+        bt = {"name": self.descriptor_name}
+        out = from_boutiques(bt, self.package_name)
+
+        assert isinstance(out, ir.Interface)
+        assert out.package.name == self.package_name
+        assert isinstance(out.command.body, ir.Param.Struct)
+        assert out.command.base.name == self.descriptor_name
+
+    @pytest.mark.parametrize("descriptor_name", (123, ["list of str"]))
+    @pytest.mark.skip
+    def test_invalid_descriptor(self, descriptor_name: Any) -> None:
+        bt = {"name": descriptor_name}
+        with pytest.raises(TypeError):
+            from_boutiques(bt, self.package_name)
diff --git a/tests/frontend/boutiques/test_docs.py b/tests/frontend/boutiques/test_docs.py
new file mode 100644
index 0000000..7794960
--- /dev/null
+++ b/tests/frontend/boutiques/test_docs.py
@@ -0,0 +1,60 @@
+from typing import Any
+
+import pytest
+
+import styx.ir.core as ir
+from styx.frontend.boutiques.core import from_boutiques
+
+
+class TestDocumentation:
+    # NOTE: 'literature' unable to be tested
+    package_name = "My package"
+    descriptor_name = "My descriptor"
+
+    @pytest.mark.parametrize("desc", ("A short description", None))
+    def test_valid_description(self, desc: str | None) -> None:
+        bt = {"name": self.descriptor_name, "description": desc}
+        out = from_boutiques(bt, self.package_name)
+        assert isinstance(out.command.base.docs, ir.Documentation)
+        assert out.command.base.docs.description == desc
+
+    @pytest.mark.parametrize("desc", (["A short description"], 123))
+    @pytest.mark.skip
+    def test_invalid_description_type(self, desc: Any) -> None:
+        bt = {"name": self.descriptor_name, "description": desc}
+        with pytest.raises(TypeError):
+            from_boutiques(bt, self.package_name)
+
+    # NOTE: Can only pass a single string of author(s) via boutiques
+    def test_valid_authors(self) -> None:
+        authors = "Author One"
+        bt = {"name": self.descriptor_name, "author": authors}
+        out = from_boutiques(bt, self.package_name)
+
+        assert isinstance(out.command.base.docs.authors, list)
+        assert out.command.base.docs.authors == [authors]
+
+    @pytest.mark.parametrize("authors", (["Author One"], 123))
+    @pytest.mark.skip
+    def test_invalid_author_type(self, authors: Any) -> None:
+        bt = {"name": self.descriptor_name, "author": authors}
+
+        with pytest.raises(TypeError):
+            from_boutiques(bt, self.package_name)
+
+    # NOTE: Can only pass a single string of url(s) via boutiques
+    def test_valid_urls(self) -> None:
+        urls = "https://url.com"
+        bt = {"name": self.descriptor_name, "url": urls}
+        out = from_boutiques(bt, self.package_name)
+
+        assert isinstance(out.command.base.docs.urls, list)
+        assert out.command.base.docs.urls == [urls]
+
+    @pytest.mark.parametrize("urls", (["https://url.com"], 123))
+    @pytest.mark.skip
+    def test_invalid_urls_type(self, urls: Any) -> None:
+        bt = {"name": self.descriptor_name, "url": urls}
+
+        with pytest.raises(TypeError):
+            from_boutiques(bt, self.package_name)
diff --git a/tests/frontend/boutiques/test_inputs.py b/tests/frontend/boutiques/test_inputs.py
new file mode 100644
index 0000000..330e364
--- /dev/null
+++ b/tests/frontend/boutiques/test_inputs.py
@@ -0,0 +1,127 @@
+import styx.ir.core as ir
+from styx.frontend.boutiques.core import from_boutiques
+
+
+class TestPrimitiveParams:
+    """Test primitive param types.
+
+    Main difference in primitive types between boutiques and IR are:
+
+    - IR has separate int and float types, boutiques just "Number"
+    - Boutiques "Flag" type maps to IR bool which is encoded differently.
+    """
+
+    package_name = "My package"
+    descriptor_name = "My descriptor"
+
+    def test_int(self) -> None:
+        bt = {
+            "name": self.descriptor_name,
+            "command-line": "dummy [X]",
+            "inputs": [
+                {
+                    "id": "x",
+                    "value-key": "[X]",
+                    "type": "Number",
+                    "integer": True,
+                }
+            ],
+        }
+        out = from_boutiques(bt, self.package_name)
+
+        assert isinstance(out.command.body, ir.Param.Struct)
+        groups = out.command.body.groups
+        assert len(groups) == 2
+        param = groups[1].cargs[0].tokens[0]
+        assert isinstance(param, ir.Param)
+        assert isinstance(param.body, ir.Param.Int)
+
+    def test_float(self) -> None:
+        bt = {
+            "name": self.descriptor_name,
+            "command-line": "dummy [X]",
+            "inputs": [
+                {
+                    "id": "x",
+                    "value-key": "[X]",
+                    "type": "Number",
+                    # "integer": False, # Default is float
+                }
+            ],
+        }
+        out = from_boutiques(bt, self.package_name)
+
+        assert isinstance(out.command.body, ir.Param.Struct)
+        groups = out.command.body.groups
+        assert len(groups) == 2
+        param = groups[1].cargs[0].tokens[0]
+        assert isinstance(param, ir.Param)
+        assert isinstance(param.body, ir.Param.Float)
+
+    def test_file(self) -> None:
+        bt = {
+            "name": self.descriptor_name,
+            "command-line": "dummy [X]",
+            "inputs": [
+                {
+                    "id": "x",
+                    "value-key": "[X]",
+                    "type": "File",
+                }
+            ],
+        }
+        out = from_boutiques(bt, self.package_name)
+
+        assert isinstance(out.command.body, ir.Param.Struct)
+        groups = out.command.body.groups
+        assert len(groups) == 2
+        param = groups[1].cargs[0].tokens[0]
+        assert isinstance(param, ir.Param)
+        assert isinstance(param.body, ir.Param.File)
+
+    def test_string(self) -> None:
+        bt = {
+            "name": self.descriptor_name,
+            "command-line": "dummy [X]",
+            "inputs": [
+                {
+                    "id": "x",
+                    "value-key": "[X]",
+                    "type": "String",
+                }
+            ],
+        }
+        out = from_boutiques(bt, self.package_name)
+
+        assert isinstance(out.command.body, ir.Param.Struct)
+        groups = out.command.body.groups
+        assert len(groups) == 2
+        param = groups[1].cargs[0].tokens[0]
+        assert isinstance(param, ir.Param)
+        assert isinstance(param.body, ir.Param.String)
+
+    def test_bool(self) -> None:
+        bt = {
+            "name": self.descriptor_name,
+            "command-line": "dummy [X]",
+            "inputs": [
+                {
+                    "id": "x",
+                    "value-key": "[X]",
+                    "type": "Flag",
+                    "command-line-flag": "--x",
+                }
+            ],
+        }
+        out = from_boutiques(bt, self.package_name)
+
+        assert isinstance(out.command.body, ir.Param.Struct)
+        groups = out.command.body.groups
+        assert len(groups) == 2
+        param = groups[1].cargs[0].tokens[0]
+        assert isinstance(param, ir.Param)
+        assert isinstance(param.body, ir.Param.Bool)
+        assert param.body.value_true == ["--x"]
+        assert param.body.value_false == []
+        assert not param.nullable
+        assert param.default_value is False  # check identity to ensure it's False and not None
diff --git a/tests/frontend/boutiques/test_metadata.py b/tests/frontend/boutiques/test_metadata.py
new file mode 100644
index 0000000..e925251
--- /dev/null
+++ b/tests/frontend/boutiques/test_metadata.py
@@ -0,0 +1,44 @@
+from typing import Any
+
+import pytest
+
+import styx.ir.core as ir
+from styx.frontend.boutiques.core import from_boutiques
+
+
+class TestMetadata:
+    package_name = "My package"
+    descriptor_name = "My descriptor"
+
+    @pytest.mark.parametrize("version", ("0.0.0", None))
+    def test_valid_version(self, version: str | None) -> None:
+        bt = {"name": self.descriptor_name, "tool-version": version}
+        out = from_boutiques(bt, self.package_name)
+
+        assert isinstance(out.package, ir.Package)
+        assert out.package.name == self.package_name
+        assert out.package.version == version
+
+    @pytest.mark.parametrize("version", (1.23, ["version"]))
+    @pytest.mark.skip
+    def test_invalid_version_type(self, version: Any) -> None:
+        bt = {"name": self.descriptor_name, "tool-version": version}
+
+        with pytest.raises(TypeError):
+            from_boutiques(bt, self.package_name)
+
+    @pytest.mark.parametrize("image", ("container:version", None))
+    def test_valid_docker(self, image: str | None) -> None:
+        bt = {"name": self.descriptor_name, "container-image": {"image": image}}
+        out = from_boutiques(bt, self.package_name)
+        assert isinstance(out.package, ir.Package)
+        assert out.package.name == self.package_name
+        assert out.package.docker == image
+
+    @pytest.mark.parametrize("image", (123, ["list of str"]))
+    @pytest.mark.skip
+    def test_invalid_docker_type(self, image: Any) -> None:
+        bt = {"name": self.descriptor_name, "container-image": {"image": image}}
+
+        with pytest.raises(TypeError):
+            from_boutiques(bt, self.package_name)
diff --git a/tests/frontend/boutiques/test_outputs.py b/tests/frontend/boutiques/test_outputs.py
new file mode 100644
index 0000000..e69de29
diff --git a/tests/legacy/__init__.py b/tests/legacy/__init__.py
new file mode 100644
index 0000000..0ecdab8
--- /dev/null
+++ b/tests/legacy/__init__.py
@@ -0,0 +1 @@
+"""Legacy tests."""
diff --git a/tests/test_carg_building.py b/tests/legacy/test_carg_building.py
similarity index 86%
rename from tests/test_carg_building.py
rename to tests/legacy/test_carg_building.py
index 109bde7..0797722 100644
--- a/tests/test_carg_building.py
+++ b/tests/legacy/test_carg_building.py
@@ -1,8 +1,8 @@
 """Test command line argument building."""
 
-import tests.utils.dummy_runner
-from tests.utils.compile_boutiques import boutiques2python
-from tests.utils.dynmodule import (
+import tests.legacy.utils.dummy_runner
+from tests.legacy.utils.compile_boutiques import boutiques2python
+from tests.legacy.utils.dynmodule import (
     BT_TYPE_FILE,
     BT_TYPE_FLAG,
     BT_TYPE_NUMBER,
@@ -29,7 +29,7 @@ def test_positional_string_arg() -> None:
     compiled_module = boutiques2python(model)
 
     test_module = dynamic_module(compiled_module, "test_module")
-    dummy_runner = tests.utils.dummy_runner.DummyRunner()
+    dummy_runner = tests.legacy.utils.dummy_runner.DummyRunner()
     test_module.dummy(runner=dummy_runner, x="my_string")
 
     assert dummy_runner.last_cargs is not None
@@ -53,7 +53,7 @@ def test_positional_number_arg() -> None:
     compiled_module = boutiques2python(model)
 
     test_module = dynamic_module(compiled_module, "test_module")
-    dummy_runner = tests.utils.dummy_runner.DummyRunner()
+    dummy_runner = tests.legacy.utils.dummy_runner.DummyRunner()
     test_module.dummy(runner=dummy_runner, x="123")
 
     assert dummy_runner.last_cargs is not None
@@ -77,7 +77,7 @@ def test_positional_file_arg() -> None:
     compiled_module = boutiques2python(model)
 
     test_module = dynamic_module(compiled_module, "test_module")
-    dummy_runner = tests.utils.dummy_runner.DummyRunner()
+    dummy_runner = tests.legacy.utils.dummy_runner.DummyRunner()
     test_module.dummy(runner=dummy_runner, x="/my/file.txt")
 
     assert dummy_runner.last_cargs is not None
@@ -102,7 +102,7 @@ def test_flag_arg() -> None:
     compiled_module = boutiques2python(model)
 
     test_module = dynamic_module(compiled_module, "test_module")
-    dummy_runner = tests.utils.dummy_runner.DummyRunner()
+    dummy_runner = tests.legacy.utils.dummy_runner.DummyRunner()
     test_module.dummy(runner=dummy_runner, x="my_string")
 
     assert dummy_runner.last_cargs is not None
@@ -127,7 +127,7 @@ def test_named_arg() -> None:
     compiled_module = boutiques2python(model)
 
     test_module = dynamic_module(compiled_module, "test_module")
-    dummy_runner = tests.utils.dummy_runner.DummyRunner()
+    dummy_runner = tests.legacy.utils.dummy_runner.DummyRunner()
     test_module.dummy(runner=dummy_runner, x="my_string")
 
     assert dummy_runner.last_cargs is not None
@@ -161,11 +161,20 @@ def test_list_of_strings_arg() -> None:
     compiled_module = boutiques2python(model)
 
     test_module = dynamic_module(compiled_module, "test_module")
-    dummy_runner = tests.utils.dummy_runner.DummyRunner()
-    test_module.dummy(runner=dummy_runner, x=["my_string1", "my_string2"], y=["my_string3", "my_string4"])
+    dummy_runner = tests.legacy.utils.dummy_runner.DummyRunner()
+    test_module.dummy(
+        runner=dummy_runner,
+        x=["my_string1", "my_string2"],
+        y=["my_string3", "my_string4"],
+    )
 
     assert dummy_runner.last_cargs is not None
-    assert dummy_runner.last_cargs == ["dummy", "my_string1", "my_string2", "my_string3 my_string4"]
+    assert dummy_runner.last_cargs == [
+        "dummy",
+        "my_string1",
+        "my_string2",
+        "my_string3 my_string4",
+    ]
 
 
 def test_list_of_numbers_arg() -> None:
@@ -195,7 +204,7 @@ def test_list_of_numbers_arg() -> None:
     compiled_module = boutiques2python(model)
 
     test_module = dynamic_module(compiled_module, "test_module")
-    dummy_runner = tests.utils.dummy_runner.DummyRunner()
+    dummy_runner = tests.legacy.utils.dummy_runner.DummyRunner()
     test_module.dummy(runner=dummy_runner, x=[1, 2], y=[3, 4])
 
     assert dummy_runner.last_cargs is not None
@@ -220,7 +229,7 @@ def test_static_args() -> None:
     compiled_module = boutiques2python(model)
 
     test_module = dynamic_module(compiled_module, "test_module")
-    dummy_runner = tests.utils.dummy_runner.DummyRunner()
+    dummy_runner = tests.legacy.utils.dummy_runner.DummyRunner()
     test_module.dummy(runner=dummy_runner, x="my_string")
 
     assert dummy_runner.last_cargs is not None
@@ -265,7 +274,7 @@ def test_arg_order() -> None:
     compiled_module = boutiques2python(model)
 
     test_module = dynamic_module(compiled_module, "test_module")
-    dummy_runner = tests.utils.dummy_runner.DummyRunner()
+    dummy_runner = tests.legacy.utils.dummy_runner.DummyRunner()
     test_module.dummy(a="aaa", b="bbb", runner=dummy_runner)
 
     assert dummy_runner.last_cargs is not None
diff --git a/tests/test_default_values.py b/tests/legacy/test_default_values.py
similarity index 78%
rename from tests/test_default_values.py
rename to tests/legacy/test_default_values.py
index 5e85f35..23cbe92 100644
--- a/tests/test_default_values.py
+++ b/tests/legacy/test_default_values.py
@@ -1,8 +1,8 @@
 """Input argument default value tests."""
 
-import tests.utils.dummy_runner
-from tests.utils.compile_boutiques import boutiques2python
-from tests.utils.dynmodule import (
+import tests.legacy.utils.dummy_runner
+from tests.legacy.utils.compile_boutiques import boutiques2python
+from tests.legacy.utils.dynmodule import (
     BT_TYPE_STRING,
     boutiques_dummy,
     dynamic_module,
@@ -27,7 +27,7 @@ def test_default_string_arg() -> None:
     compiled_module = boutiques2python(model)
 
     test_module = dynamic_module(compiled_module, "test_module")
-    dummy_runner = tests.utils.dummy_runner.DummyRunner()
+    dummy_runner = tests.legacy.utils.dummy_runner.DummyRunner()
     test_module.dummy(runner=dummy_runner)
 
     assert dummy_runner.last_cargs is not None
diff --git a/tests/test_numeric_ranges.py b/tests/legacy/test_numeric_ranges.py
similarity index 87%
rename from tests/test_numeric_ranges.py
rename to tests/legacy/test_numeric_ranges.py
index a331244..1c87476 100644
--- a/tests/test_numeric_ranges.py
+++ b/tests/legacy/test_numeric_ranges.py
@@ -2,9 +2,9 @@
 
 import pytest
 
-import tests.utils.dummy_runner
-from tests.utils.compile_boutiques import boutiques2python
-from tests.utils.dynmodule import (
+import tests.legacy.utils.dummy_runner
+from tests.legacy.utils.compile_boutiques import boutiques2python
+from tests.legacy.utils.dynmodule import (
     BT_TYPE_NUMBER,
     boutiques_dummy,
     dynamic_module,
@@ -30,7 +30,7 @@ def test_below_range_minimum_inclusive() -> None:
     compiled_module = boutiques2python(model)
 
     test_module = dynamic_module(compiled_module, "test_module")
-    dummy_runner = tests.utils.dummy_runner.DummyRunner()
+    dummy_runner = tests.legacy.utils.dummy_runner.DummyRunner()
     with pytest.raises(ValueError):
         test_module.dummy(runner=dummy_runner, x=4)
 
@@ -54,7 +54,7 @@ def test_above_range_maximum_inclusive() -> None:
     compiled_module = boutiques2python(model)
 
     test_module = dynamic_module(compiled_module, "test_module")
-    dummy_runner = tests.utils.dummy_runner.DummyRunner()
+    dummy_runner = tests.legacy.utils.dummy_runner.DummyRunner()
     with pytest.raises(ValueError):
         test_module.dummy(runner=dummy_runner, x=6)
 
@@ -79,7 +79,7 @@ def test_above_range_maximum_exclusive() -> None:
     compiled_module = boutiques2python(model)
 
     test_module = dynamic_module(compiled_module, "test_module")
-    dummy_runner = tests.utils.dummy_runner.DummyRunner()
+    dummy_runner = tests.legacy.utils.dummy_runner.DummyRunner()
     with pytest.raises(ValueError):
         test_module.dummy(runner=dummy_runner, x=5)
 
@@ -104,7 +104,7 @@ def test_below_range_minimum_exclusive() -> None:
     compiled_module = boutiques2python(model)
 
     test_module = dynamic_module(compiled_module, "test_module")
-    dummy_runner = tests.utils.dummy_runner.DummyRunner()
+    dummy_runner = tests.legacy.utils.dummy_runner.DummyRunner()
     with pytest.raises(ValueError):
         test_module.dummy(runner=dummy_runner, x=5)
 
@@ -129,7 +129,7 @@ def test_outside_range() -> None:
     compiled_module = boutiques2python(model)
 
     test_module = dynamic_module(compiled_module, "test_module")
-    dummy_runner = tests.utils.dummy_runner.DummyRunner()
+    dummy_runner = tests.legacy.utils.dummy_runner.DummyRunner()
     with pytest.raises(ValueError):
         test_module.dummy(runner=dummy_runner, x=11)
 
diff --git a/tests/test_output_files.py b/tests/legacy/test_output_files.py
similarity index 89%
rename from tests/test_output_files.py
rename to tests/legacy/test_output_files.py
index 7123dab..cde64ed 100644
--- a/tests/test_output_files.py
+++ b/tests/legacy/test_output_files.py
@@ -1,8 +1,8 @@
 """Test output file paths."""
 
-import tests.utils.dummy_runner
-from tests.utils.compile_boutiques import boutiques2python
-from tests.utils.dynmodule import (
+import tests.legacy.utils.dummy_runner
+from tests.legacy.utils.compile_boutiques import boutiques2python
+from tests.legacy.utils.dynmodule import (
     BT_TYPE_FILE,
     BT_TYPE_NUMBER,
     boutiques_dummy,
@@ -34,7 +34,7 @@ def test_output_file() -> None:
     compiled_module = boutiques2python(model)
 
     test_module = dynamic_module(compiled_module, "test_module")
-    dummy_runner = tests.utils.dummy_runner.DummyRunner()
+    dummy_runner = tests.legacy.utils.dummy_runner.DummyRunner()
     out = test_module.dummy(runner=dummy_runner, x=5)
 
     assert dummy_runner.last_cargs is not None
@@ -67,7 +67,7 @@ def test_output_file_with_template() -> None:
     compiled_module = boutiques2python(model)
 
     test_module = dynamic_module(compiled_module, "test_module")
-    dummy_runner = tests.utils.dummy_runner.DummyRunner()
+    dummy_runner = tests.legacy.utils.dummy_runner.DummyRunner()
     out = test_module.dummy(runner=dummy_runner, x=5)
 
     assert dummy_runner.last_cargs is not None
@@ -101,7 +101,7 @@ def test_output_file_with_template_and_stripped_extensions() -> None:
     compiled_module = boutiques2python(model)
 
     test_module = dynamic_module(compiled_module, "test_module")
-    dummy_runner = tests.utils.dummy_runner.DummyRunner()
+    dummy_runner = tests.legacy.utils.dummy_runner.DummyRunner()
     out = test_module.dummy(runner=dummy_runner, x="in.txt")
 
     assert dummy_runner.last_cargs is not None
diff --git a/tests/utils/__init__.py b/tests/legacy/utils/__init__.py
similarity index 100%
rename from tests/utils/__init__.py
rename to tests/legacy/utils/__init__.py
diff --git a/tests/utils/compile_boutiques.py b/tests/legacy/utils/compile_boutiques.py
similarity index 100%
rename from tests/utils/compile_boutiques.py
rename to tests/legacy/utils/compile_boutiques.py
diff --git a/tests/utils/dummy_runner.py b/tests/legacy/utils/dummy_runner.py
similarity index 100%
rename from tests/utils/dummy_runner.py
rename to tests/legacy/utils/dummy_runner.py
diff --git a/tests/utils/dynmodule.py b/tests/legacy/utils/dynmodule.py
similarity index 100%
rename from tests/utils/dynmodule.py
rename to tests/legacy/utils/dynmodule.py