diff --git a/podman-compose-backup.py b/podman-compose-backup.py
index af1cf6b..02ac3a2 100644
--- a/podman-compose-backup.py
+++ b/podman-compose-backup.py
@@ -44,6 +44,16 @@ from attrs import define, field
 from podman_compose import normalize, rec_merge, rec_subs
 import yaml
 
+from podman_compose_tools.defs.compose import (
+    ComposeDef,
+    ComposeVersion,
+    ServiceName,
+    ContainerName,
+    ComposeServiceDef,
+    VolumeName,
+    PublicVolumeName,
+    ComposeVolumeDef,
+)
 from podman_compose_tools.executor import (
     ArgCommand,
     BinaryExecutor,
@@ -62,35 +72,10 @@ from podman_compose_tools.executor.base import (
 
 ProjectName = NewType("ProjectName", str)
 
-ComposeVersion = NewType("ComposeVersion", str)
-ContainerName = NewType("ContainerName", str)
-PublicVolumeName = NewType("PublicVolumeName", str)
-
-ServiceName = NewType("ServiceName", str)
-VolumeName = NewType("VolumeName", str)
 
 LabelDict: TypeAlias = Mapping[str, str]
 
 
-class _ComposeDefRequired(TypedDict):
-    _dirname: Path
-    version: ComposeVersion
-
-
-class ComposeDef(_ComposeDefRequired, total=False):
-    services: Mapping[ServiceName, ComposeServiceDef]
-    volumes: Mapping[VolumeName, Optional[ComposeVolumeDef]]
-
-
-class ComposeServiceDef(TypedDict, total=False):
-    container_name: ContainerName
-    depends_on: Sequence[ServiceName]
-
-
-class ComposeVolumeDef(TypedDict, total=False):
-    name: PublicVolumeName
-
-
 class VolumeInspectDef(TypedDict):
     Name: PublicVolumeName
     Driver: str
diff --git a/podman_compose_tools/defs/compose/__init__.py b/podman_compose_tools/defs/compose/__init__.py
new file mode 100644
index 0000000..2f5d2d4
--- /dev/null
+++ b/podman_compose_tools/defs/compose/__init__.py
@@ -0,0 +1,14 @@
+from .compose import (
+    ComposeDef,
+    ComposeVersion,
+)
+from .service import (
+    ServiceName,
+    ContainerName,
+    ServiceDef as ComposeServiceDef,
+)
+from .volume import (
+    VolumeName,
+    PublicVolumeName,
+    VolumeDef as ComposeVolumeDef,
+)
diff --git a/podman_compose_tools/defs/compose/compose.py b/podman_compose_tools/defs/compose/compose.py
new file mode 100644
index 0000000..154de40
--- /dev/null
+++ b/podman_compose_tools/defs/compose/compose.py
@@ -0,0 +1,20 @@
+from __future__ import annotations
+
+from pathlib import Path
+from typing import Mapping, NewType, Optional, TypedDict
+
+from .service import ServiceName, ServiceDef
+from .volume import VolumeName, VolumeDef
+
+
+ComposeVersion = NewType("ComposeVersion", str)
+
+
+class _ComposeDefRequired(TypedDict):
+    _dirname: Path
+    version: ComposeVersion
+
+
+class ComposeDef(_ComposeDefRequired, total=False):
+    services: Mapping[ServiceName, ServiceDef]
+    volumes: Mapping[VolumeName, Optional[VolumeDef]]
diff --git a/podman_compose_tools/defs/compose/service.py b/podman_compose_tools/defs/compose/service.py
new file mode 100644
index 0000000..1617776
--- /dev/null
+++ b/podman_compose_tools/defs/compose/service.py
@@ -0,0 +1,12 @@
+from __future__ import annotations
+
+from typing import Literal, NewType, Sequence, TypeAlias, TypedDict
+
+
+ServiceName = NewType("ServiceName", str)
+ContainerName = NewType("ContainerName", str)
+
+
+class ServiceDef(TypedDict, total=False):
+    container_name: ContainerName
+    depends_on: Sequence[ServiceName]
diff --git a/podman_compose_tools/defs/compose/volume.py b/podman_compose_tools/defs/compose/volume.py
new file mode 100644
index 0000000..a0129ea
--- /dev/null
+++ b/podman_compose_tools/defs/compose/volume.py
@@ -0,0 +1,11 @@
+from __future__ import annotations
+
+from typing import NewType, TypedDict
+
+
+VolumeName = NewType("VolumeName", str)
+PublicVolumeName = NewType("PublicVolumeName", str)
+
+
+class VolumeDef(TypedDict, total=False):
+    name: PublicVolumeName