diff --git a/pyproject.toml b/pyproject.toml
index df908ec..bda1181 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -20,7 +20,7 @@ classifiers = [
     "Topic :: Scientific/Engineering :: GIS",
     "Typing :: Typed",
 ]
-version = "0.4.0"
+version = "0.5.0"
 dependencies = ["pydantic>=2.3,<3"]
 
 [project.optional-dependencies]
diff --git a/src/edr_pydantic/parameter.py b/src/edr_pydantic/parameter.py
index 466dbde..c2a31f7 100644
--- a/src/edr_pydantic/parameter.py
+++ b/src/edr_pydantic/parameter.py
@@ -7,6 +7,7 @@
 from pydantic import RootModel
 
 from .base_model import EdrBaseModel
+from .extent import Extent
 from .observed_property import ObservedProperty
 from .unit import Unit
 
@@ -26,6 +27,7 @@ class Parameter(EdrBaseModel, extra="allow"):
     description: Optional[str] = None
     unit: Optional[Unit] = None
     observedProperty: ObservedProperty  # noqa: N815
+    extent: Optional[Extent] = None
     measurementType: Optional[MeasurementType] = None  # noqa: N815
 
     @model_validator(mode="after")
diff --git a/tests/test_data/parameter-with-extent.json b/tests/test_data/parameter-with-extent.json
new file mode 100644
index 0000000..ad521ec
--- /dev/null
+++ b/tests/test_data/parameter-with-extent.json
@@ -0,0 +1,44 @@
+{
+    "type": "Parameter",
+    "description": "Temperature for Specific altitude above MSL",
+    "unit": {
+        "label": "K",
+        "symbol": {
+            "value": "K",
+            "type": "http://qudt.org/vocab/unit/K"
+        }
+    },
+    "observedProperty": {
+        "id": "http://codes.wmo.int/grib2/codeflag/4.2/_0-0-0",
+        "label": "Temperature_altitude_above_msl"
+    },
+    "extent": {
+        "spatial": {
+            "bbox": [
+                [
+                    -15.0,
+                    48.0,
+                    5.0,
+                    62.0
+                ]
+            ],
+            "crs": "GEOGCS[\"WGS 84\",DATUM[\"WGS_1984\",SPHEROID[\"WGS 84\",6378137,298.257223563,AUTHORITY[\"EPSG\",\"7030\"]],AUTHORITY[\"EPSG\",\"6326\"]],PRIMEM[\"Greenwich\",0,AUTHORITY[\"EPSG\",\"8901\"]],UNIT[\"degree\",0.01745329251994328,AUTHORITY[\"EPSG\",\"9122\"]],AUTHORITY[\"EPSG\",\"4326\"]]"
+        },
+        "temporal": {
+            "interval": [
+                [
+                    "2020-04-19T11:00:00Z",
+                    "2020-06-30T09:00:00Z"
+                ]
+            ],
+            "values": [
+                "2020-04-19T11:00:00Z/2020-06-30T09:00:00Z"
+            ],
+            "trs": "TIMECRS[\"DateTime\",TDATUM[\"Gregorian Calendar\"],CS[TemporalDateTime,1],AXIS[\"Time (T)\",future]]"
+        }
+    },
+    "measurementType": {
+        "method": "instantaneous",
+        "period": "PT0S"
+    }
+}
diff --git a/tests/test_edr.py b/tests/test_edr.py
index 81c6da8..7064a10 100644
--- a/tests/test_edr.py
+++ b/tests/test_edr.py
@@ -19,6 +19,7 @@
     ("landing-page.json", LandingPageModel),
     ("doc-example-extent.json", Extent),
     ("parameter-names.json", RootModel[Dict[str, Parameter]]),
+    ("parameter-with-extent.json", Parameter),
 ]