diff --git a/foamlib/__init__.py b/foamlib/__init__.py
index df95c60..9cd8975 100644
--- a/foamlib/__init__.py
+++ b/foamlib/__init__.py
@@ -1,6 +1,6 @@
 __version__ = "0.1.3"
 
-from ._cases import FoamCase, AsyncFoamCase, FoamTimeDirectory
+from ._cases import FoamCase, AsyncFoamCase, FoamTimeDirectory, FoamCaseBase
 from ._dictionaries import (
     FoamFile,
     FoamFieldFile,
@@ -15,6 +15,7 @@
     "FoamCase",
     "AsyncFoamCase",
     "FoamTimeDirectory",
+    "FoamCaseBase",
     "FoamFile",
     "FoamFieldFile",
     "FoamDictionary",
diff --git a/foamlib/_cases.py b/foamlib/_cases.py
index 2ca5cdb..fcb72ce 100644
--- a/foamlib/_cases.py
+++ b/foamlib/_cases.py
@@ -25,7 +25,7 @@
 from ._dictionaries import FoamFile, FoamFieldFile
 
 
-class _FoamCaseBase(Sequence["FoamTimeDirectory"]):
+class FoamCaseBase(Sequence["FoamTimeDirectory"]):
     def __init__(self, path: Union[Path, str]):
         self.path = Path(path).absolute()
         if not self.path.is_dir():
@@ -271,7 +271,7 @@ def __str__(self) -> str:
         return str(self.path)
 
 
-class FoamCase(_FoamCaseBase):
+class FoamCase(FoamCaseBase):
     """
     An OpenFOAM case.
 
@@ -407,7 +407,7 @@ def clone(self, dest: Union[Path, str]) -> "FoamCase":
         return FoamCase(dest)
 
 
-class AsyncFoamCase(_FoamCaseBase):
+class AsyncFoamCase(FoamCaseBase):
     """
     An OpenFOAM case with asynchronous support.