diff --git a/src/ibek/entity_factory.py b/src/ibek/entity_factory.py
index 1f154994e..2bdf14c12 100644
--- a/src/ibek/entity_factory.py
+++ b/src/ibek/entity_factory.py
@@ -15,8 +15,8 @@
 from ibek.globals import JINJA
 
 from .ioc import Entity, EnumVal, clear_entity_model_ids
-from .params import Define, EnumParam, IdParam, ObjectParam
-from .support import EntityDefinition, Support
+from .params import EnumParam, IdParam, ObjectParam
+from .support import EntityModel, Support
 from .utils import UTILS
 
 
@@ -56,19 +56,12 @@ def make_entity_models(self, definition_yaml: List[Path]) -> List[Type[Entity]]:
         return list(self._entity_models.values())
 
     def _make_entity_model(
-        self, definition: EntityDefinition, support: Support
+        self, definition: EntityModel, support: Support
     ) -> Type[Entity]:
         """
         Create an Entity Model from a Definition instance and a Support instance.
         """
 
-        def add_defines(s: dict[str, Define]) -> None:
-            if s:
-                # add in the pre_defines or post_defines as Args in the Entity
-                for name, value in s.items():
-                    typ = getattr(builtins, str(value.type))
-                    add_arg(name, typ, value.description, value.value)
-
         def add_arg(name, typ, description, default):
             if default is None:
                 default = PydanticUndefined
@@ -100,11 +93,6 @@ def add_arg(name, typ, description, default):
         # fully qualified name of the Entity class including support module
         full_name = f"{support.module}.{definition.name}"
 
-        # add in the calculated values Jinja Templates as Fields in the Entity
-        # these are the pre_values that should be Jinja rendered before any
-        # Args (or post values)
-        add_defines(definition.pre_defines)
-
         # add in each of the arguments as a Field in the Entity
         for name, arg in definition.params.items():
             type: Any
@@ -132,9 +120,6 @@ def add_arg(name, typ, description, default):
                 type = getattr(builtins, arg.type)
             add_arg(name, type, arg.description, getattr(arg, "default"))  # type: ignore
 
-        # add in the calculated values Jinja Templates as Fields in the Entity
-        add_defines(definition.post_defines)
-
         # add the type literal which discriminates between the different Entity classes
         typ = Literal[full_name]  # type: ignore
         args["type"] = (typ, Field(description=definition.description))
diff --git a/src/ibek/definition.py b/src/ibek/entity_model.py
similarity index 97%
rename from src/ibek/definition.py
rename to src/ibek/entity_model.py
index 3d4299dc3..8e1c12076 100644
--- a/src/ibek/definition.py
+++ b/src/ibek/entity_model.py
@@ -121,9 +121,9 @@ class EntityPVI(BaseSettings):
 ]
 
 
-class EntityDefinition(BaseSettings):
+class EntityModel(BaseSettings):
     """
-    A single definition of a class of Entity that an IOC instance may instantiate
+    A Model for a class of Entity that an IOC instance may instantiate
     """
 
     name: str = Field(
diff --git a/src/ibek/gen_scripts.py b/src/ibek/gen_scripts.py
index c69115c79..f32bb6f1f 100644
--- a/src/ibek/gen_scripts.py
+++ b/src/ibek/gen_scripts.py
@@ -9,7 +9,7 @@
 
 from ibek.utils import UTILS
 
-from .definition import Database
+from .entity_model import Database
 from .globals import TEMPLATES
 from .ioc import Entity
 from .render import Render
diff --git a/src/ibek/ioc.py b/src/ibek/ioc.py
index 58847f9bf..fc445682e 100644
--- a/src/ibek/ioc.py
+++ b/src/ibek/ioc.py
@@ -5,7 +5,8 @@
 
 from __future__ import annotations
 
-import json
+import ast
+import builtins
 from enum import Enum
 from typing import Any, Dict, List, Sequence
 
@@ -13,10 +14,10 @@
     Field,
     model_validator,
 )
+from pydantic.fields import FieldInfo
 
-from .definition import EntityDefinition
+from .entity_model import EntityModel
 from .globals import BaseSettings
-from .params import IdParam
 from .utils import UTILS
 
 # a global dict of all entity instances indexed by their ID
@@ -54,60 +55,69 @@ class Entity(BaseSettings):
     entity_enabled: bool = Field(
         description="enable or disable this entity instance", default=True
     )
-    __definition__: EntityDefinition
+    __definition__: EntityModel
+
+    def _process_field(self: Entity, name: str, value: Any, typ: str):
+        """
+        Process an Entity field - doing jinja rendering, type coercion and
+        object id storage/lookup as required.
+        """
+
+        if isinstance(value, str):
+            # Jinja expansion always performed on string fields
+            value = UTILS.render(self, value)
+            if typ in ["list", "int", "float", "bool"]:
+                # coerce the rendered parameter to its intended type
+                try:
+                    cast_type = getattr(builtins, typ)
+                    value = cast_type(ast.literal_eval(value))
+                except:
+                    print(f"ERROR: decoding field '{name}', value '{value}' as {typ}")
+                    raise
+
+        if typ == "object":
+            # look up the actual object by it's id
+            if isinstance(value, str):
+                value = get_entity_by_id(value)
+
+        # If this field is not pre-existing, add it into the model instance.
+        # This is how pre/post_defines are added.
+        if name not in self.model_fields:
+            self.model_fields[name] = FieldInfo(annotation=str, default=value)
+
+        # update the model instance attribute with the rendered value
+        setattr(self, name, value)
+
+        if typ == "id":
+            # add this entity to the global id index
+            if value in id_to_entity:
+                raise ValueError(f"Duplicate id {value} in {list(id_to_entity)}")
+            id_to_entity[value] = self
 
     @model_validator(mode="after")
     def add_ibek_attributes(self):
         """
         Whole Entity model validation
+
+        Do jinja rendering of pre_defines/ parameters / post_defines
+        in the correct order.
+
+        Also adds  pre_define and post_defines to the model instance, making
+        them available for the phase 2 (final) jinja rendering performed in
+        ibek.runtime_cmds.generate().
         """
 
-        # find the id field in this Entity if it has one
-        ids = {
-            name
-            for name, value in self.__definition__.params.items()
-            if isinstance(value, IdParam)
-        }
+        if self.__definition__.pre_defines:
+            for name, define in self.__definition__.pre_defines.items():
+                self._process_field(name, define.value, define.type)
 
-        entity_dict = self.model_dump()
-        for arg, value in entity_dict.items():
-            model_field = self.model_fields[arg]
+        if self.__definition__.params:
+            for name, parameter in self.__definition__.params.items():
+                self._process_field(name, getattr(self, name), parameter.type)
 
-            if isinstance(value, str):
-                # Jinja expansion of any of the Entity's string args/values
-                value = UTILS.render(entity_dict, value)
-                # this is a cheesy test - any better ideas please let me know
-                if "Union" in str(model_field.annotation):
-                    # Args that were non strings and have been rendered by Jinja
-                    # must be coerced back into their original type
-                    try:
-                        # The following replace are to make the string json compatible
-                        # (maybe we should python decode instead of json.loads)
-                        value = value.replace("'", '"')
-                        value = value.replace("True", "true")
-                        value = value.replace("False", "false")
-                        value = json.loads(value)
-                    except:
-                        print(
-                            f"ERROR: fail to decode {value} as a {model_field.annotation}"
-                        )
-                        raise
-
-            if model_field.annotation == object:
-                # look up the actual object by it's id
-                if isinstance(value, str):
-                    value = get_entity_by_id(value)
-
-            # update this entity instance with the rendered value
-            setattr(self, arg, value)
-            # update the entity_dict with the rendered value
-            entity_dict[arg] = value
-
-            if arg in ids:
-                # add this entity to the global id index
-                if value in id_to_entity:
-                    raise ValueError(f"Duplicate id {value} in {list(id_to_entity)}")
-                id_to_entity[value] = self
+        if self.__definition__.post_defines:
+            for name, define in self.__definition__.post_defines.items():
+                self._process_field(name, define.value, define.type)
 
         return self
 
diff --git a/src/ibek/params.py b/src/ibek/params.py
index f069a230b..8831caebe 100644
--- a/src/ibek/params.py
+++ b/src/ibek/params.py
@@ -17,7 +17,7 @@
 ]
 
 
-class DefinesTypes(Enum):
+class DefineTypes(Enum):
     """The type of a value"""
 
     string = "str"
@@ -34,14 +34,14 @@ def __repr__(self):
 
 
 class Define(BaseSettings):
-    """A calculated string value for a definition"""
+    """A calculated value for an Entity Model"""
 
     description: str = Field(
         description="Description of what the value will be used for"
     )
     value: Any = Field(description="The contents of the value")
-    type: DefinesTypes = Field(
-        description="The type of the value", default=DefinesTypes.string
+    type: DefineTypes | None = Field(
+        description="The type of the value", default=DefineTypes.string
     )
 
 
diff --git a/src/ibek/render.py b/src/ibek/render.py
index 8782fc311..649d541bd 100644
--- a/src/ibek/render.py
+++ b/src/ibek/render.py
@@ -4,7 +4,7 @@
 
 from typing import Callable, List, Optional, Sequence, Union
 
-from .definition import Comment, Script, Text, When
+from .entity_model import Comment, Script, Text, When
 from .ioc import Entity
 from .utils import UTILS
 
diff --git a/src/ibek/render_db.py b/src/ibek/render_db.py
index 120f77e23..7e1bced90 100644
--- a/src/ibek/render_db.py
+++ b/src/ibek/render_db.py
@@ -6,7 +6,7 @@
 from dataclasses import dataclass
 from typing import Any, Dict, List, Mapping, Optional, Sequence, Tuple
 
-from ibek.definition import Database
+from ibek.entity_model import Database
 from ibek.ioc import Entity
 from ibek.utils import UTILS
 
diff --git a/src/ibek/runtime_cmds/commands.py b/src/ibek/runtime_cmds/commands.py
index 89f5fe553..f77af8b96 100644
--- a/src/ibek/runtime_cmds/commands.py
+++ b/src/ibek/runtime_cmds/commands.py
@@ -8,8 +8,8 @@
 from pvi._format.template import format_template
 from pvi.device import Device
 
-from ibek.definition import Database
 from ibek.entity_factory import EntityFactory
+from ibek.entity_model import Database
 from ibek.gen_scripts import create_boot_script, create_db_script
 from ibek.globals import GLOBALS, NaturalOrderGroup
 from ibek.ioc import IOC, Entity
diff --git a/src/ibek/support.py b/src/ibek/support.py
index fee58d870..33239ba97 100644
--- a/src/ibek/support.py
+++ b/src/ibek/support.py
@@ -9,7 +9,7 @@
 
 from pydantic import Field
 
-from .definition import EntityDefinition
+from .entity_model import EntityModel
 from .globals import BaseSettings
 
 
@@ -26,7 +26,7 @@ class Support(BaseSettings):
     )
 
     module: str = Field(description="Support module name, normally the repo name")
-    defs: Sequence[EntityDefinition] = Field(
+    defs: Sequence[EntityModel] = Field(
         description="The definitions an IOC can create using this module"
     )
 
diff --git a/tests/samples/schemas/fastVacuum.ibek.ioc.schema.json b/tests/samples/schemas/fastVacuum.ibek.ioc.schema.json
index b58459a77..b23309d85 100644
--- a/tests/samples/schemas/fastVacuum.ibek.ioc.schema.json
+++ b/tests/samples/schemas/fastVacuum.ibek.ioc.schema.json
@@ -95,46 +95,6 @@
           "default": 0,
           "description": "union of <class 'int'> and jinja representation of {typ}",
           "title": "Timeout"
-        },
-        "gaugeNum": {
-          "anyOf": [
-            {
-              "description": "jinja that renders to <class 'int'>",
-              "pattern": ".*\\{\\{.*\\}\\}.*",
-              "type": "string"
-            },
-            {
-              "description": "auto gauge count",
-              "type": "integer"
-            }
-          ],
-          "default": "{{ _global.incrementor(master, start=1) }}",
-          "description": "union of <class 'int'> and jinja representation of {typ}",
-          "title": "Gaugenum"
-        },
-        "fan": {
-          "default": "{{ \"%02d\" % (gaugeNum / 7 + 1) }}",
-          "description": "fan number",
-          "title": "Fan",
-          "type": "string"
-        },
-        "mask": {
-          "default": "{{ _global.incrementor(\"mask_{}\".format(master), 2, 2**gaugeNum) }}",
-          "description": "mask for the channel",
-          "title": "Mask",
-          "type": "string"
-        },
-        "lnk_no": {
-          "default": "{{ ((gaugeNum - 1) % 6) + 1 }}",
-          "description": "link number",
-          "title": "Lnk No",
-          "type": "string"
-        },
-        "gaugePV": {
-          "default": "{{ master.device }}:GAUGE:{{id}}_0",
-          "description": "Gauge PV",
-          "title": "Gaugepv",
-          "type": "string"
         }
       },
       "required": [
@@ -186,41 +146,9 @@
         },
         "device": {
           "default": "{{dom}}-VA-FAST-01",
-          "description": "device name",
+          "description": "Device prefix",
           "title": "Device",
           "type": "string"
-        },
-        "waveform_nelm": {
-          "anyOf": [
-            {
-              "description": "jinja that renders to <class 'int'>",
-              "pattern": ".*\\{\\{.*\\}\\}.*",
-              "type": "string"
-            },
-            {
-              "description": "waveform element count",
-              "type": "integer"
-            }
-          ],
-          "default": 500,
-          "description": "union of <class 'int'> and jinja representation of {typ}",
-          "title": "Waveform Nelm"
-        },
-        "combined_nelm": {
-          "anyOf": [
-            {
-              "description": "jinja that renders to <class 'int'>",
-              "pattern": ".*\\{\\{.*\\}\\}.*",
-              "type": "string"
-            },
-            {
-              "description": "total waveform element count",
-              "type": "integer"
-            }
-          ],
-          "default": "{{ 6 * waveform_nelm }}",
-          "description": "union of <class 'int'> and jinja representation of {typ}",
-          "title": "Combined Nelm"
         }
       },
       "required": [
diff --git a/tests/samples/schemas/gauges.ibek.ioc.schema.json b/tests/samples/schemas/gauges.ibek.ioc.schema.json
index 6230cda5a..5a18c93b9 100644
--- a/tests/samples/schemas/gauges.ibek.ioc.schema.json
+++ b/tests/samples/schemas/gauges.ibek.ioc.schema.json
@@ -212,17 +212,17 @@
           "title": "Gauge1"
         },
         "gauge2": {
-          "default": "{{gauge1.name}}",
+          "default": "{{gauge1}}",
           "description": "Second gauge",
           "title": "Gauge2"
         },
         "gauge3": {
-          "default": "{{gauge1.name}}\n",
+          "default": "{{gauge1}}\n",
           "description": "Third gauge",
           "title": "Gauge3"
         },
         "gauge4": {
-          "default": "{{gauge1.name}}\n",
+          "default": "{{gauge1}}\n",
           "description": "Fourth gauge",
           "title": "Gauge4"
         }
diff --git a/tests/samples/schemas/ibek.support.schema.json b/tests/samples/schemas/ibek.support.schema.json
index b1dc86889..1af29ed48 100644
--- a/tests/samples/schemas/ibek.support.schema.json
+++ b/tests/samples/schemas/ibek.support.schema.json
@@ -114,7 +114,7 @@
     },
     "Define": {
       "additionalProperties": false,
-      "description": "A calculated string value for a definition",
+      "description": "A calculated value for an Entity Model",
       "properties": {
         "description": {
           "description": "Description of what the value will be used for",
@@ -126,9 +126,12 @@
           "title": "Value"
         },
         "type": {
-          "allOf": [
+          "anyOf": [
             {
-              "$ref": "#/$defs/DefinesTypes"
+              "$ref": "#/$defs/DefineTypes"
+            },
+            {
+              "type": "null"
             }
           ],
           "default": "str",
@@ -142,7 +145,7 @@
       "title": "Define",
       "type": "object"
     },
-    "DefinesTypes": {
+    "DefineTypes": {
       "description": "The type of a value",
       "enum": [
         "str",
@@ -151,12 +154,12 @@
         "bool",
         "list"
       ],
-      "title": "DefinesTypes",
+      "title": "DefineTypes",
       "type": "string"
     },
-    "EntityDefinition": {
+    "EntityModel": {
       "additionalProperties": false,
-      "description": "A single definition of a class of Entity that an IOC instance may instantiate",
+      "description": "A Model for a class of Entity that an IOC instance may instantiate",
       "properties": {
         "name": {
           "description": "Publish Definition as type <module>.<name> for IOC instances",
@@ -313,7 +316,7 @@
         "name",
         "description"
       ],
-      "title": "EntityDefinition",
+      "title": "EntityModel",
       "type": "object"
     },
     "EntityPVI": {
@@ -704,7 +707,7 @@
     "defs": {
       "description": "The definitions an IOC can create using this module",
       "items": {
-        "$ref": "#/$defs/EntityDefinition"
+        "$ref": "#/$defs/EntityModel"
       },
       "title": "Defs",
       "type": "array"
diff --git a/tests/samples/schemas/ipac.ibek.ioc.schema.json b/tests/samples/schemas/ipac.ibek.ioc.schema.json
index 4ea7b3b1e..173bf6a5b 100644
--- a/tests/samples/schemas/ipac.ibek.ioc.schema.json
+++ b/tests/samples/schemas/ipac.ibek.ioc.schema.json
@@ -176,12 +176,6 @@
           "default": 1,
           "description": "union of <class 'int'> and jinja representation of {typ}",
           "title": "Count"
-        },
-        "number": {
-          "default": "{{  _global.incrementor(\"InterruptVector\", start=192, stop=255, increment=count) }}",
-          "description": "Interrupt Vector number",
-          "title": "Number",
-          "type": "string"
         }
       },
       "required": [
@@ -535,12 +529,6 @@
         "interrupt_vector": {
           "description": "Interrupt Vector reserved with epics.InterruptVectorVME, count=1",
           "title": "Interrupt Vector"
-        },
-        "card_id": {
-          "default": "{{ _global.incrementor(\"Carriers\", start=0) }}",
-          "description": "Carrier Card Identifier",
-          "title": "Card Id",
-          "type": "string"
         }
       },
       "required": [
diff --git a/tests/samples/schemas/listarg.ibek.schema.json b/tests/samples/schemas/listarg.ibek.schema.json
index ff09d96f3..ecb817a57 100644
--- a/tests/samples/schemas/listarg.ibek.schema.json
+++ b/tests/samples/schemas/listarg.ibek.schema.json
@@ -18,12 +18,6 @@
           "title": "Entity Enabled",
           "type": "boolean"
         },
-        "name": {
-          "default": "Dave Lister",
-          "description": "name of the character",
-          "title": "Name",
-          "type": "string"
-        },
         "age": {
           "anyOf": [
             {
@@ -77,61 +71,6 @@
           "default": "{{ name == 'Dave Lister' }}",
           "description": "union of <class 'bool'> and jinja representation of {typ}",
           "title": "Is Human"
-        },
-        "cryo_years": {
-          "anyOf": [
-            {
-              "description": "jinja that renders to <class 'int'>",
-              "pattern": ".*\\{\\{.*\\}\\}.*",
-              "type": "string"
-            },
-            {
-              "description": "years in cryogenic sleep",
-              "type": "integer"
-            }
-          ],
-          "default": 3000000,
-          "description": "union of <class 'int'> and jinja representation of {typ}",
-          "title": "Cryo Years"
-        },
-        "friends": {
-          "anyOf": [
-            {
-              "description": "jinja that renders to <class 'list'>",
-              "pattern": ".*\\{\\{.*\\}\\}.*",
-              "type": "string"
-            },
-            {
-              "description": "friends of Lister",
-              "items": {},
-              "type": "array"
-            }
-          ],
-          "default": [
-            "Rimmer",
-            "Cat",
-            "Kryten",
-            "Holly"
-          ],
-          "description": "union of <class 'list'> and jinja representation of {typ}",
-          "title": "Friends"
-        },
-        "time_vortex": {
-          "anyOf": [
-            {
-              "description": "jinja that renders to <class 'list'>",
-              "pattern": ".*\\{\\{.*\\}\\}.*",
-              "type": "string"
-            },
-            {
-              "description": "friends after the Time Hole episode",
-              "items": {},
-              "type": "array"
-            }
-          ],
-          "default": "{{ (friends * 3) | sort }}",
-          "description": "union of <class 'list'> and jinja representation of {typ}",
-          "title": "Time Vortex"
         }
       },
       "required": [
diff --git a/tests/samples/schemas/technosoft.ibek.ioc.schema.json b/tests/samples/schemas/technosoft.ibek.ioc.schema.json
index 5b8960761..8642cd8be 100644
--- a/tests/samples/schemas/technosoft.ibek.ioc.schema.json
+++ b/tests/samples/schemas/technosoft.ibek.ioc.schema.json
@@ -61,29 +61,6 @@
           "description": "TML Configuration",
           "title": "Config",
           "type": "string"
-        },
-        "axisConfiguration": {
-          "anyOf": [
-            {
-              "description": "jinja that renders to <class 'list'>",
-              "pattern": ".*\\{\\{.*\\}\\}.*",
-              "type": "string"
-            },
-            {
-              "description": "collects the axis configuration from axis entities",
-              "items": {},
-              "type": "array"
-            }
-          ],
-          "default": [],
-          "description": "union of <class 'list'> and jinja representation of {typ}",
-          "title": "Axisconfiguration"
-        },
-        "axisNum": {
-          "default": "{{ \"axes_{}\".format(controllerName) }}",
-          "description": "A name for the axis counter (used to generate unique axis numbers)",
-          "title": "Axisnum",
-          "type": "string"
         }
       },
       "required": [
@@ -433,12 +410,6 @@
           "description": "Axis configuration string to add to the controller configuration",
           "title": "Config",
           "type": "string"
-        },
-        "axisConfiguration": {
-          "default": "{{ controller.axisConfiguration.append(CONFIG) }}",
-          "description": "Adds an axis configuration entry to the controller's list",
-          "title": "Axisconfiguration",
-          "type": "string"
         }
       },
       "required": [
diff --git a/tests/samples/schemas/utils.ibek.ioc.schema.json b/tests/samples/schemas/utils.ibek.ioc.schema.json
index 033fc5ac9..7662b55e7 100644
--- a/tests/samples/schemas/utils.ibek.ioc.schema.json
+++ b/tests/samples/schemas/utils.ibek.ioc.schema.json
@@ -22,18 +22,6 @@
           "description": "A name for an interrupt vector variable",
           "title": "Name",
           "type": "string"
-        },
-        "test_global_var": {
-          "default": "{{  _global.set(\"magic_global\", 42) }}",
-          "description": "test global variable setter",
-          "title": "Test Global Var",
-          "type": "string"
-        },
-        "get_global": {
-          "default": "{{  _global.get(\"magic_global\") }}",
-          "description": "test global variable getter",
-          "title": "Get Global",
-          "type": "string"
         }
       },
       "required": [
diff --git a/tests/samples/support/fastVacuum.ibek.support.yaml b/tests/samples/support/fastVacuum.ibek.support.yaml
index bcd96c779..c663dcc0a 100644
--- a/tests/samples/support/fastVacuum.ibek.support.yaml
+++ b/tests/samples/support/fastVacuum.ibek.support.yaml
@@ -40,6 +40,8 @@ defs:
         type: str
         description: |-
           Device prefix
+        default: |-
+          {{dom}}-VA-FAST-01
 
     post_defines:
       device:
diff --git a/tests/samples/support/listarg.ibek.support.yaml b/tests/samples/support/listarg.ibek.support.yaml
index a0611cc0b..ded280126 100644
--- a/tests/samples/support/listarg.ibek.support.yaml
+++ b/tests/samples/support/listarg.ibek.support.yaml
@@ -39,6 +39,13 @@ defs:
         value: |-
           Dave Lister
 
+      cryo_years:
+        description: |-
+          years in cryogenic sleep
+        type: int
+        value: 3000000
+        # https://en.wikipedia.org/wiki/Dave_Lister#:~:text=As%20a%20result%2C%20Holly%20keeps,radiation%20levels%20return%20to%20normal.
+
     params:
       # example of using aliases to merge multiple dictionaries into this one
       <<: [*params1, *params2]
@@ -52,13 +59,6 @@ defs:
           {{ name == 'Dave Lister' }}
 
     post_defines:
-      cryo_years:
-        description: |-
-          years in cryogenic sleep
-        type: int
-        value: 3000000
-        # https://en.wikipedia.org/wiki/Dave_Lister#:~:text=As%20a%20result%2C%20Holly%20keeps,radiation%20levels%20return%20to%20normal.
-
       # example type list value not using Jinja
       friends:
         description: |-
diff --git a/tests/test_unit.py b/tests/test_unit.py
index 9df46f131..d8855b816 100644
--- a/tests/test_unit.py
+++ b/tests/test_unit.py
@@ -11,7 +11,7 @@
 from ibek.ioc import id_to_entity
 from ibek.ioc_factory import IocFactory
 from ibek.params import IdParam, ObjectParam
-from ibek.support import EntityDefinition, Support
+from ibek.support import EntityModel, Support
 from ibek.utils import UTILS
 
 
@@ -22,12 +22,12 @@ def test_object_references(entity_factory):
     support = Support(
         module="mymodule",
         defs=[
-            EntityDefinition(
+            EntityModel(
                 name="port",
                 description="a port",
                 params={"name": IdParam(description="an id")},
             ),
-            EntityDefinition(
+            EntityModel(
                 name="device",
                 description="a device",
                 params={"port": ObjectParam(description="the port")},