diff --git a/seam/models.py b/seam/models.py
index 8339979a..155c0ca7 100644
--- a/seam/models.py
+++ b/seam/models.py
@@ -120,7 +120,7 @@ async def list(
         raise NotImplementedError()
 
 
-class AbstractSeamWithoutWorkspace:
+class AbstractSeamWithoutWorkspace(abc.ABC):
     wait_for_action_attempt: Optional[Union[bool, Dict[str, float]]]
 
     @abc.abstractmethod
@@ -145,7 +145,7 @@ def from_personal_access_token(
         raise NotImplementedError
 
 
-class AbstractAsyncSeamWithoutWorkspace:
+class AbstractAsyncSeamWithoutWorkspace(abc.ABC):
     wait_for_action_attempt: Optional[Union[bool, Dict[str, float]]]
 
     @abc.abstractmethod
diff --git a/test/abstract_models_test.py b/test/abstract_models_test.py
new file mode 100644
index 00000000..9b95e51c
--- /dev/null
+++ b/test/abstract_models_test.py
@@ -0,0 +1,18 @@
+import pytest
+
+from seam.models import (
+    AbstractAsyncSeamWithoutWorkspace,
+    AbstractSeamWithoutWorkspace,
+)
+
+
+def test_abstract_seam_without_workspace_cannot_be_instantiated():
+    with pytest.raises(TypeError, match="abstract"):
+        # pylint: disable-next=abstract-class-instantiated
+        AbstractSeamWithoutWorkspace("seam_at_token")  # type: ignore[abstract]
+
+
+def test_abstract_async_seam_without_workspace_cannot_be_instantiated():
+    with pytest.raises(TypeError, match="abstract"):
+        # pylint: disable-next=abstract-class-instantiated
+        AbstractAsyncSeamWithoutWorkspace("seam_at_token")  # type: ignore[abstract]