diff --git a/tests/integ/sagemaker/serve/test_schema_builder.py b/tests/integ/sagemaker/serve/test_schema_builder.py
index 1a50678cd7..fa3c55f4cc 100644
--- a/tests/integ/sagemaker/serve/test_schema_builder.py
+++ b/tests/integ/sagemaker/serve/test_schema_builder.py
@@ -92,6 +92,13 @@ def test_model_builder_happy_path_with_task_provided_local_schema_mode(
         model_metadata={"HF_TASK": task_provided},
         instance_type=instance_type_provided,
         sagemaker_session=sagemaker_session,
+        env_vars={
+            # Force plain HTTPS model download in the container. HF Hub repos are now
+            # backed by Xet storage, and the DLC's hf_transfer path returns 403 against
+            # the Xet CDN, so the container fails the ping health check on startup.
+            "HF_HUB_ENABLE_HF_TRANSFER": "0",
+            "HF_HUB_DISABLE_XET": "1",
+        },
     )
 
     model = model_builder.build(sagemaker_session=sagemaker_session)
@@ -169,6 +176,13 @@ def test_model_builder_happy_path_with_task_provided_remote_schema_mode(
         model_metadata={"HF_TASK": task_provided},
         instance_type=instance_type_provided,
         sagemaker_session=sagemaker_session,
+        env_vars={
+            # Force plain HTTPS model download in the container. HF Hub repos are now
+            # backed by Xet storage, and the DLC's hf_transfer path returns 403 against
+            # the Xet CDN, so the container fails the ping health check on startup.
+            "HF_HUB_ENABLE_HF_TRANSFER": "0",
+            "HF_HUB_DISABLE_XET": "1",
+        },
     )
     model = model_builder.build(sagemaker_session=sagemaker_session)
 
diff --git a/tests/integ/sagemaker/serve/test_serve_tei.py b/tests/integ/sagemaker/serve/test_serve_tei.py
index 4c824da401..af22a18531 100644
--- a/tests/integ/sagemaker/serve/test_serve_tei.py
+++ b/tests/integ/sagemaker/serve/test_serve_tei.py
@@ -47,7 +47,12 @@ def model_builder_model_schema_builder(sagemaker_session):
         schema_builder=SchemaBuilder(sample_input, loaded_response),
         env_vars={
             # Add this to bypass JumpStart model mapping
-            "HF_MODEL_ID": "BAAI/bge-m3"
+            "HF_MODEL_ID": "BAAI/bge-m3",
+            # Force plain HTTPS model download in the container. HF Hub repos are now
+            # backed by Xet storage, and the DLC's hf_transfer path returns 403 against
+            # the Xet CDN, so the container fails the ping health check on startup.
+            "HF_HUB_ENABLE_HF_TRANSFER": "0",
+            "HF_HUB_DISABLE_XET": "1",
         },
     )
 
diff --git a/tests/unit/sagemaker/serve/builder/test_js_builder.py b/tests/unit/sagemaker/serve/builder/test_js_builder.py
index 0f976ba060..2cc1decb41 100644
--- a/tests/unit/sagemaker/serve/builder/test_js_builder.py
+++ b/tests/unit/sagemaker/serve/builder/test_js_builder.py
@@ -1272,12 +1272,14 @@ def test_jumpstart_model_provider_calls_jumpstart_speculative_decoding(
 
         mock_js_speculative_decoding.assert_called_once()
 
+    @patch("sagemaker.serve.builder.jumpstart_builder.JumpStartModel")
     @patch("sagemaker.serve.builder.jumpstart_builder._capture_telemetry", side_effect=None)
     @patch.object(ModelBuilder, "_get_serve_setting", autospec=True)
     def test_optimize_quantize_and_compile_for_jumpstart(
         self,
         mock_serve_settings,
         mock_telemetry,
+        mock_js_model,
     ):
         mock_sagemaker_session = Mock()
         mock_metadata_config = Mock()
@@ -1319,6 +1321,10 @@ def test_optimize_quantize_and_compile_for_jumpstart(
 
         model_builder.pysdk_model = mock_pysdk_model
 
+        # Avoid a real JumpStartModel construction (which would hit S3 for the
+        # JumpStart manifest); return a deterministic env for neuron lookup.
+        mock_js_model.return_value.env = {"SAGEMAKER_ENV": "1"}
+
         out_put = model_builder._optimize_for_jumpstart(
             accept_eula=True,
             quantization_config={