diff --git a/clients/python/tests/regression_test.py b/clients/python/tests/regression_test.py
index 0310f3879..4645833ea 100644
--- a/clients/python/tests/regression_test.py
+++ b/clients/python/tests/regression_test.py
@@ -1,4 +1,5 @@
 import pytest
+import requests
 
 from model_registry import ModelRegistry
 from model_registry.types.artifacts import ModelArtifact
@@ -99,3 +100,35 @@ async def test_create_standalone_model_artifact(client: ModelRegistry):
     assert mv.id
     mv_ma = await client._api.upsert_model_version_artifact(new_ma, mv.id)
     assert mv_ma.id == new_ma.id
+
+@pytest.mark.e2e
+async def test_patch_model_artifacts_artifact_type(client: ModelRegistry):
+    """Patching Artifacts makes the model registry server panic.
+
+    reported with https://issues.redhat.com/browse/RHOAIENG-16932
+    """
+    name = "test_model"
+    version = "1.0.0"
+    rm = client.register_model(
+        name,
+        "s3",
+        model_format_name="test_format",
+        model_format_version="test_version",
+        version=version,
+    )
+    assert rm.id
+    mv = client.get_model_version(name, version)
+    assert mv
+    assert mv.id
+    ma = client.get_model_artifact(name, version)
+    assert ma
+    assert ma.id
+
+    payload = { "modelFormatName": "foo", "artifactType": "model-artifact" }
+    from .conftest import REGISTRY_HOST, REGISTRY_PORT
+    response = requests.patch(url=f"{REGISTRY_HOST}:{REGISTRY_PORT}/api/model_registry/v1alpha3/artifacts/{ma.id}", json=payload, timeout=10, headers={"Content-Type": "application/json"})
+    assert response.status_code == 200
+    ma = client.get_model_artifact(name, version)
+    assert ma
+    assert ma.id
+    assert ma.model_format_name == "foo"
diff --git a/internal/converter/openapi_reconciler_util.go b/internal/converter/openapi_reconciler_util.go
index e2b8544c8..071912a7f 100644
--- a/internal/converter/openapi_reconciler_util.go
+++ b/internal/converter/openapi_reconciler_util.go
@@ -6,18 +6,28 @@ import (
 
 func UpdateExistingArtifact(genc OpenAPIReconciler, source OpenapiUpdateWrapper[openapi.Artifact]) (openapi.Artifact, error) {
 	art := InitWithExisting(source)
+
 	if source.Update == nil {
 		return art, nil
 	}
-	ma, err := genc.UpdateExistingModelArtifact(OpenapiUpdateWrapper[openapi.ModelArtifact]{Existing: art.ModelArtifact, Update: source.Update.ModelArtifact})
-	if err != nil {
-		return art, err
+
+	if source.Update.ModelArtifact != nil {
+		ma, err := genc.UpdateExistingModelArtifact(OpenapiUpdateWrapper[openapi.ModelArtifact]{Existing: art.ModelArtifact, Update: source.Update.ModelArtifact})
+		if err != nil {
+			return art, err
+		}
+
+		art.ModelArtifact = &ma
 	}
-	da, err := genc.UpdateExistingDocArtifact(OpenapiUpdateWrapper[openapi.DocArtifact]{Existing: art.DocArtifact, Update: source.Update.DocArtifact})
-	if err != nil {
-		return art, err
+
+	if source.Update.DocArtifact != nil {
+		da, err := genc.UpdateExistingDocArtifact(OpenapiUpdateWrapper[openapi.DocArtifact]{Existing: art.DocArtifact, Update: source.Update.DocArtifact})
+		if err != nil {
+			return art, err
+		}
+
+		art.DocArtifact = &da
 	}
-	art.DocArtifact = &da
-	art.ModelArtifact = &ma
+
 	return art, nil
 }
diff --git a/internal/server/openapi/api_model_registry_service_service.go b/internal/server/openapi/api_model_registry_service_service.go
index d22b38c25..3d5211b4a 100644
--- a/internal/server/openapi/api_model_registry_service_service.go
+++ b/internal/server/openapi/api_model_registry_service_service.go
@@ -492,7 +492,8 @@ func (s *ModelRegistryServiceAPIService) UpdateArtifact(ctx context.Context, art
 	}
 	if artifactUpdate.DocArtifactUpdate != nil {
 		entity.DocArtifact.Id = &artifactId
-	} else {
+	}
+	if artifactUpdate.ModelArtifactUpdate != nil {
 		entity.ModelArtifact.Id = &artifactId
 	}
 	existing, err := s.coreApi.GetArtifactById(artifactId)