diff --git a/tests/e2e/singlecard/test_guided_decoding.py b/tests/e2e/singlecard/test_guided_decoding.py
index 04587d0..ff9f952 100644
--- a/tests/e2e/singlecard/test_guided_decoding.py
+++ b/tests/e2e/singlecard/test_guided_decoding.py
@@ -30,7 +30,7 @@ from tests.e2e.conftest import VllmRunner
 os.environ["PYTORCH_NPU_ALLOC_CONF"] = "max_split_size_mb:256"
 MODEL_NAME = "Qwen/Qwen2.5-0.5B-Instruct"
 
-GuidedDecodingBackend = ["xgrammar", "guidance"]
+GuidedDecodingBackend = ["xgrammar", "guidance", "outlines"]
 
 
 @pytest.fixture(scope="module")
@@ -120,6 +120,9 @@ def test_guided_json_completion(guided_decoding_backend: str,
 
 @pytest.mark.parametrize("guided_decoding_backend", GuidedDecodingBackend)
 def test_guided_regex(guided_decoding_backend: str, sample_regex):
+    if guided_decoding_backend == "outlines":
+        pytest.skip("Outlines doesn't support regex-based guided decoding.")
+
     sampling_params = SamplingParams(
         temperature=0.8,
         top_p=0.95,