diff --git a/tests/fixtures/xquik-openapi31.yaml b/tests/fixtures/xquik-openapi31.yaml
new file mode 100644
index 0000000..c86df85
--- /dev/null
+++ b/tests/fixtures/xquik-openapi31.yaml
@@ -0,0 +1,58 @@
+openapi: 3.1.0
+info:
+  title: Xquik API
+  version: "1.0"
+servers:
+  - url: https://xquik.com
+components:
+  securitySchemes:
+    apiKey:
+      type: apiKey
+      name: X-API-Key
+      in: header
+  schemas:
+    TweetSearchResponse:
+      type: object
+      required:
+        - data
+      properties:
+        data:
+          type: array
+          items:
+            type: object
+            required:
+              - id
+              - text
+            properties:
+              id:
+                type: string
+              text:
+                type: string
+paths:
+  /api/v1/x/tweets/search:
+    get:
+      operationId: searchTweets
+      summary: Search recent public posts
+      security:
+        - apiKey: []
+      parameters:
+        - name: q
+          in: query
+          required: true
+          schema:
+            type: string
+            minLength: 1
+        - name: limit
+          in: query
+          required: false
+          schema:
+            type: integer
+            minimum: 1
+            maximum: 100
+      responses:
+        "200":
+          description: Search results
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/TweetSearchResponse"
diff --git a/tests/test_parser.py b/tests/test_parser.py
index 3aceed1..b258174 100644
--- a/tests/test_parser.py
+++ b/tests/test_parser.py
@@ -6,7 +6,7 @@
 
 from apighost.parser import _infer_type, get_param_pattern, parse_spec
 
-from . import PETSTORE_YAML
+from . import FIXTURES_DIR, PETSTORE_YAML
 
 
 def test_load_yaml():
@@ -31,6 +31,29 @@ def test_parse_endpoints():
     assert ("GET", "/pets/{petId}/photos") in methods
 
 
+def test_parse_xquik_openapi31_endpoint():
+    """Test parsing an OpenAPI 3.1 endpoint with API key security."""
+    spec = parse_spec(FIXTURES_DIR / "xquik-openapi31.yaml")
+
+    assert spec.title == "Xquik API"
+    assert spec.version == "1.0"
+    assert spec.servers == ["https://xquik.com"]
+    assert len(spec.endpoints) == 1
+
+    endpoint = spec.endpoints[0]
+    assert endpoint.operation_id == "searchTweets"
+    assert endpoint.method == "GET"
+    assert endpoint.path == "/api/v1/x/tweets/search"
+    assert endpoint.security == [{"apiKey": []}]
+    assert [param.name for param in endpoint.parameters] == ["q", "limit"]
+    assert endpoint.parameters[0].required is True
+    assert endpoint.parameters[0].schema_ref["type"] == "string"
+    assert endpoint.parameters[1].schema_ref["type"] == "integer"
+    assert 200 in endpoint.responses
+    response_schema = endpoint.responses[200].schema_ref
+    assert response_schema["properties"]["data"]["type"] == "array"
+
+
 def test_parse_endpoint_details():
     """Test endpoint details."""
     spec = parse_spec(PETSTORE_YAML)