diff --git a/fixlib/fixlib/baseresources.py b/fixlib/fixlib/baseresources.py
index 411ec1e4fa..997539f502 100644
--- a/fixlib/fixlib/baseresources.py
+++ b/fixlib/fixlib/baseresources.py
@@ -296,6 +296,8 @@ class BaseResource(ABC):
     _categories: ClassVar[List[Category]] = []
     # Link to the cloud providers product documentation of this resource kind.
     _docs_url: ClassVar[Optional[str]] = None
+    # Mark this class as exportable. Use False for internal model classes without instances.
+    _model_export: ClassVar[bool] = True
 
     ################################################################################
     # Instance Variables
diff --git a/fixlib/fixlib/core/model_check.py b/fixlib/fixlib/core/model_check.py
index 9d811b2035..9b4e807cd4 100644
--- a/fixlib/fixlib/core/model_check.py
+++ b/fixlib/fixlib/core/model_check.py
@@ -174,12 +174,10 @@ def dynamic_import(name: str) -> List[Type[Any]]:
         *dynamic_import("fix_plugin_github.resources.GithubResource"),
         *dynamic_import("fix_plugin_k8s.resources.KubernetesResource"),
         *dynamic_import("fix_plugin_onelogin.OneLoginResource"),
-        *dynamic_import("fix_plugin_onprem.resources.OnpremResource"),
         *dynamic_import("fix_plugin_posthog.resources.PosthogResource"),
         *dynamic_import("fix_plugin_random.resources.RandomResource"),
         *dynamic_import("fix_plugin_scarf.resources.ScarfResource"),
         *dynamic_import("fix_plugin_slack.resources.SlackResource"),
-        *dynamic_import("fix_plugin_vsphere.resources.VSphereResource"),
         *base,
     }
 
diff --git a/fixlib/fixlib/core/model_export.py b/fixlib/fixlib/core/model_export.py
index 53196bca45..3636c32af9 100644
--- a/fixlib/fixlib/core/model_export.py
+++ b/fixlib/fixlib/core/model_export.py
@@ -69,7 +69,7 @@ def transitive_classes(classes: Set[type], walk_subclasses: bool = True) -> Set[
     def check(to_check: type) -> None:
         clazz = optional_origin(to_check)
         if clazz in all_classes:
-            pass
+            return
         elif is_dict(clazz):
             key_type, value_type = dict_types(to_check)
             check(key_type)
@@ -77,6 +77,8 @@ def check(to_check: type) -> None:
         elif is_collection(clazz):
             check(type_arg(to_check))
         elif attrs.has(clazz):
+            if getattr(clazz, "_model_export", True) is False:
+                return
             resolve_types(clazz)
             all_classes.add(clazz)
             for mro_clazz in clazz.mro()[1:]:
diff --git a/fixlib/test/core/model_export_test.py b/fixlib/test/core/model_export_test.py
index 0dfb8489c5..f628b98ada 100644
--- a/fixlib/test/core/model_export_test.py
+++ b/fixlib/test/core/model_export_test.py
@@ -70,6 +70,13 @@ class DataClassOther(DataClassBase):
     something: str
 
 
+@define(slots=False)
+class DataClassNotExported(DataClassBase):
+    _model_export: ClassVar[bool] = False
+    kind: ClassVar[str] = "other"
+    something: str
+
+
 def test_collection() -> None:
     assert is_collection(Optional[List[str]]) is True
     assert is_collection(List[str]) is True