diff --git a/api/src/opentrons/protocol_api/labware.py b/api/src/opentrons/protocol_api/labware.py
index 1e26342b61e..480af5fd009 100644
--- a/api/src/opentrons/protocol_api/labware.py
+++ b/api/src/opentrons/protocol_api/labware.py
@@ -30,7 +30,6 @@
 # remove when their usage is no longer needed
 from opentrons.protocols.labware import (  # noqa: F401
     get_labware_definition as get_labware_definition,
-    get_all_labware_definitions as get_all_labware_definitions,
     verify_definition as verify_definition,
     save_definition as save_definition,
 )
diff --git a/api/src/opentrons/protocols/api_support/constants.py b/api/src/opentrons/protocols/api_support/constants.py
index b350d970055..8da286acb62 100644
--- a/api/src/opentrons/protocols/api_support/constants.py
+++ b/api/src/opentrons/protocols/api_support/constants.py
@@ -4,5 +4,5 @@
 
 OPENTRONS_NAMESPACE = "opentrons"
 CUSTOM_NAMESPACE = "custom_beta"
-STANDARD_DEFS_PATH = Path("labware/definitions/2")
+STANDARD_DEFS_PATH = Path("labware/definitions")
 USER_DEFS_PATH = get_opentrons_path("labware_user_definitions_dir_v2")
diff --git a/api/src/opentrons/protocols/api_support/util.py b/api/src/opentrons/protocols/api_support/util.py
index 3438692de2f..da4ceff7360 100644
--- a/api/src/opentrons/protocols/api_support/util.py
+++ b/api/src/opentrons/protocols/api_support/util.py
@@ -391,13 +391,3 @@ def _check_version_wrapper(*args: Any, **kwargs: Any) -> Any:
         return cast(FuncT, _check_version_wrapper)
 
     return _set_version
-
-
-class ModifiedList(list[str]):
-    def __contains__(self, item: object) -> bool:
-        if not isinstance(item, str):
-            return False
-        for name in self:
-            if name == item.replace("-", "_").lower():
-                return True
-        return False
diff --git a/api/src/opentrons/protocols/labware.py b/api/src/opentrons/protocols/labware.py
index 02f617fd72c..ed1b7d15219 100644
--- a/api/src/opentrons/protocols/labware.py
+++ b/api/src/opentrons/protocols/labware.py
@@ -2,14 +2,12 @@
 
 import logging
 import json
-import os
 
 from pathlib import Path
-from typing import Any, AnyStr, List, Dict, Optional, Union
+from typing import Any, AnyStr, Dict, Optional, Union
 
 import jsonschema  # type: ignore
 
-from opentrons.protocols.api_support.util import ModifiedList
 from opentrons_shared_data import load_shared_data, get_shared_data_root
 from opentrons.protocols.api_support.constants import (
     OPENTRONS_NAMESPACE,
@@ -63,29 +61,6 @@ def get_labware_definition(
     return _get_standard_labware_definition(load_name, namespace, version)
 
 
-def get_all_labware_definitions() -> List[str]:
-    """
-    Return a list of standard and custom labware definitions with load_name +
-        name_space + version existing on the robot
-    """
-    labware_list = ModifiedList()
-
-    def _check_for_subdirectories(path: Union[str, Path, os.DirEntry[str]]) -> None:
-        with os.scandir(path) as top_path:
-            for sub_dir in top_path:
-                if sub_dir.is_dir():
-                    labware_list.append(sub_dir.name)
-
-    # check for standard labware
-    _check_for_subdirectories(get_shared_data_root() / STANDARD_DEFS_PATH)
-
-    # check for custom labware
-    for namespace in os.scandir(USER_DEFS_PATH):
-        _check_for_subdirectories(namespace)
-
-    return labware_list
-
-
 def save_definition(
     labware_def: LabwareDefinition, force: bool = False, location: Optional[Path] = None
 ) -> None:
@@ -114,7 +89,6 @@ def save_definition(
             f'Saving definitions to the "{OPENTRONS_NAMESPACE}" namespace '
             + "is not permitted"
         )
-
     def_path = _get_path_to_labware(load_name, namespace, version, location)
 
     if not force and def_path.is_file():
@@ -219,7 +193,6 @@ def _get_standard_labware_definition(
         Definitions Folder from the Opentrons App before
         uploading your protocol.
         """
-
     if namespace is None:
         for fallback_namespace in [OPENTRONS_NAMESPACE, CUSTOM_NAMESPACE]:
             try:
@@ -252,9 +225,21 @@ def _get_path_to_labware(
 ) -> Path:
     if namespace == OPENTRONS_NAMESPACE:
         # all labware in OPENTRONS_NAMESPACE is stored in shared data
-        return (
-            get_shared_data_root() / STANDARD_DEFS_PATH / load_name / f"{version}.json"
+        schema_3_path = (
+            get_shared_data_root()
+            / STANDARD_DEFS_PATH
+            / "3"
+            / load_name
+            / f"{version}.json"
+        )
+        schema_2_path = (
+            get_shared_data_root()
+            / STANDARD_DEFS_PATH
+            / "2"
+            / load_name
+            / f"{version}.json"
         )
+        return schema_3_path if schema_3_path.exists() else schema_2_path
     if not base_path:
         base_path = USER_DEFS_PATH
     def_path = base_path / namespace / load_name / f"{version}.json"