diff --git a/invokeai/backend/model_manager/load/load_default.py b/invokeai/backend/model_manager/load/load_default.py
index c8e02a10a3..fb9751b549 100644
--- a/invokeai/backend/model_manager/load/load_default.py
+++ b/invokeai/backend/model_manager/load/load_default.py
@@ -14,7 +14,7 @@ from invokeai.backend.model_manager import (
 )
 from invokeai.backend.model_manager.config import DiffusersConfigBase
 from invokeai.backend.model_manager.load.load_base import LoadedModel, ModelLoaderBase
-from invokeai.backend.model_manager.load.model_cache.model_cache import ModelCache
+from invokeai.backend.model_manager.load.model_cache.model_cache import ModelCache, get_model_cache_key
 from invokeai.backend.model_manager.load.model_cache.model_locker import ModelLocker
 from invokeai.backend.model_manager.load.model_util import calc_model_size_by_fs
 from invokeai.backend.model_manager.load.optimizations import skip_torch_weight_init
@@ -70,7 +70,7 @@ class ModelLoader(ModelLoaderBase):
     def _load_and_cache(self, config: AnyModelConfig, submodel_type: Optional[SubModelType] = None) -> ModelLocker:
         stats_name = ":".join([config.base, config.type, config.name, (submodel_type or "")])
         try:
-            return self._ram_cache.get(config.key, submodel_type, stats_name=stats_name)
+            return self._ram_cache.get(key=get_model_cache_key(config.key, submodel_type), stats_name=stats_name)
         except IndexError:
             pass
 
@@ -79,16 +79,11 @@ class ModelLoader(ModelLoaderBase):
         loaded_model = self._load_model(config, submodel_type)
 
         self._ram_cache.put(
-            config.key,
-            submodel_type=submodel_type,
+            get_model_cache_key(config.key, submodel_type),
             model=loaded_model,
         )
 
-        return self._ram_cache.get(
-            key=config.key,
-            submodel_type=submodel_type,
-            stats_name=stats_name,
-        )
+        return self._ram_cache.get(key=get_model_cache_key(config.key, submodel_type), stats_name=stats_name)
 
     def get_size_fs(
         self, config: AnyModelConfig, model_path: Path, submodel_type: Optional[SubModelType] = None
diff --git a/invokeai/backend/model_manager/load/model_cache/model_cache.py b/invokeai/backend/model_manager/load/model_cache/model_cache.py
index 28c1d64865..de9e31917c 100644
--- a/invokeai/backend/model_manager/load/model_cache/model_cache.py
+++ b/invokeai/backend/model_manager/load/model_cache/model_cache.py
@@ -26,6 +26,13 @@ GB = 2**30
 MB = 2**20
 
 
+def get_model_cache_key(model_key: str, submodel_type: Optional[SubModelType] = None) -> str:
+    if submodel_type:
+        return f"{model_key}:{submodel_type.value}"
+    else:
+        return model_key
+
+
 class ModelCache:
     """A cache for managing models in memory.
 
@@ -159,10 +166,8 @@ class ModelCache:
         self,
         key: str,
         model: AnyModel,
-        submodel_type: Optional[SubModelType] = None,
     ) -> None:
-        """Store model under key and optional submodel_type."""
-        key = self._make_cache_key(key, submodel_type)
+        """Insert model into the cache."""
         if key in self._cached_models:
             return
         size = calc_model_size_by_data(self.logger, model)
@@ -177,20 +182,15 @@ class ModelCache:
     def get(
         self,
         key: str,
-        submodel_type: Optional[SubModelType] = None,
         stats_name: Optional[str] = None,
     ) -> ModelLocker:
-        """
-        Retrieve model using key and optional submodel_type.
+        """Retrieve a model from the cache.
 
-        :param key: Opaque model key
-        :param submodel_type: Type of the submodel to fetch
-        :param stats_name: A human-readable id for the model for the purposes of
-        stats reporting.
+        :param key: Model key
+        :param stats_name: A human-readable id for the model for the purposes of stats reporting.
 
-        This may raise an IndexError if the model is not in the cache.
+        Raises IndexError if the model is not in the cache.
         """
-        key = self._make_cache_key(key, submodel_type)
         if key in self._cached_models:
             if self.stats:
                 self.stats.hits += 1
diff --git a/invokeai/backend/model_manager/load/model_loaders/stable_diffusion.py b/invokeai/backend/model_manager/load/model_loaders/stable_diffusion.py
index 1f57d5c199..92b80d2c7a 100644
--- a/invokeai/backend/model_manager/load/model_loaders/stable_diffusion.py
+++ b/invokeai/backend/model_manager/load/model_loaders/stable_diffusion.py
@@ -25,6 +25,7 @@ from invokeai.backend.model_manager.config import (
     DiffusersConfigBase,
     MainCheckpointConfig,
 )
+from invokeai.backend.model_manager.load.model_cache.model_cache import get_model_cache_key
 from invokeai.backend.model_manager.load.model_loader_registry import ModelLoaderRegistry
 from invokeai.backend.model_manager.load.model_loaders.generic_diffusers import GenericDiffusersLoader
 from invokeai.backend.util.silence_warnings import SilenceWarnings
@@ -132,5 +133,5 @@ class StableDiffusionDiffusersModel(GenericDiffusersLoader):
             if subtype == submodel_type:
                 continue
             if submodel := getattr(pipeline, subtype.value, None):
-                self._ram_cache.put(config.key, submodel_type=subtype, model=submodel)
+                self._ram_cache.put(get_model_cache_key(config.key, subtype), model=submodel)
         return getattr(pipeline, submodel_type.value)