diff --git a/example/app/main.py b/example/app/main.py
index 16a6569..ae19481 100644
--- a/example/app/main.py
+++ b/example/app/main.py
@@ -115,6 +115,7 @@ def most_similar(query_results, ctx, part, eval_part):
     cors_enabled=True,
     example_query=example_query,
     example_queries=example_queries,
+    enable_update=True,
 )
 
 ## Uncomment to run it directly with python app/main.py
diff --git a/src/rdflib_endpoint/sparql_router.py b/src/rdflib_endpoint/sparql_router.py
index 89c2ce1..427c52b 100644
--- a/src/rdflib_endpoint/sparql_router.py
+++ b/src/rdflib_endpoint/sparql_router.py
@@ -115,9 +115,7 @@ def _parse_preference(qpref: str) -> float:
         qparts = qpref.split("=")
         try:
             return float(qparts[1].strip())
-        except ValueError:
-            pass
-        except IndexError:
+        except (ValueError, IndexError):
             pass
         return 1.0
 
@@ -197,22 +195,10 @@ def __init__(
         elif len(self.functions) > 0:
             rdflib.plugins.sparql.CUSTOM_EVALS["evalCustomFunctions"] = self.eval_custom_functions
 
-        # TODO: use add_api_route? https://github.com/tiangolo/fastapi/blob/d666ccb62216e45ca78643b52c235ba0d2c53986/fastapi/routing.py#L548
-        @self.get(
-            self.path,
-            name="SPARQL endpoint",
-            description=self.example_markdown,
-            responses=api_responses,
-        )
-        async def sparql_endpoint(
-            request: Request, query: Optional[str] = Query(None), update: Optional[str] = None  # Not supported for GET
+        async def handle_sparql_request(
+            request: Request, query: Optional[str] = None, update: Optional[str] = None
         ) -> Response:
-            """
-            Send a SPARQL query to be executed through HTTP GET operation.
-
-            :param request: The HTTP GET request
-            :param query: SPARQL query input.
-            """
+            """Handle SPARQL requests to the GET and POST endpoints"""
             if query and update:
                 return JSONResponse(
                     status_code=400,
@@ -295,7 +281,7 @@ async def sparql_endpoint(
                         status_code=400,
                         content={"message": "Error executing the SPARQL query on the RDFLib Graph"},
                     )
-            else:  # update
+            else:  # Update
                 if not self.enable_update:
                     return JSONResponse(
                         status_code=403, content={"message": "INSERT and DELETE queries are not allowed."}
@@ -319,6 +305,25 @@ async def sparql_endpoint(
                         content={"message": "Error executing the SPARQL update on the RDFLib Graph"},
                     )
 
+        # TODO: use add_api_route? https://github.com/tiangolo/fastapi/blob/d666ccb62216e45ca78643b52c235ba0d2c53986/fastapi/routing.py#L548
+        @self.get(
+            self.path,
+            name="SPARQL endpoint",
+            description=self.example_markdown,
+            responses=api_responses,
+        )
+        async def get_sparql_endpoint(
+            request: Request,
+            query: Optional[str] = Query(None),
+        ) -> Response:
+            """
+            Send a SPARQL query to be executed through HTTP GET operation.
+
+            :param request: The HTTP GET request
+            :param query: SPARQL query input.
+            """
+            return await handle_sparql_request(request, query=query)
+
         @self.post(
             path,
             name="SPARQL endpoint",
@@ -345,11 +350,13 @@ async def post_sparql_endpoint(request: Request) -> Response:
                 query = parse.unquote(query_params[0]) if query_params else None
                 update_params = [kvp[1] for kvp in request_params if kvp[0] == "update"]
                 update = parse.unquote(update_params[0]) if update_params else None
+                # TODO: handle params `using-graph-uri` and `using-named-graph-uri`
+                # https://www.w3.org/TR/sparql11-protocol/#update-operation
             else:
                 # Response with the service description
                 query = None
                 update = None
-            return await sparql_endpoint(request, query, update)
+            return await handle_sparql_request(request, query, update)
 
     def eval_custom_functions(self, ctx: QueryContext, part: CompValue) -> List[Any]:
         """Retrieve variables from a SPARQL-query, then execute registered SPARQL functions
diff --git a/tests/test_parse_accept.py b/tests/test_parse_accept.py
index c37d7c8..73e06a4 100644
--- a/tests/test_parse_accept.py
+++ b/tests/test_parse_accept.py
@@ -6,6 +6,7 @@
     ("text/xml", "text/xml"),
     ("text/rdf+xml, text/xml, */*", "text/rdf+xml"),
     ("text/html, application/xhtml+xml, application/xml;q=0.9, */*;q=0.8", "text/html"),
+    ("text/html, application/xhtml+xml, application/xml;q=0.9, */*;q=", "text/html"),
     ("text/html;q=0.3, application/xhtml+xml, application/xml;q=0.9, */*;q=0.8", "application/xhtml+xml"),
     (
         'text/turtle;q=0.9;profile="urn:example:profile-1", text/turtle;q=0.7;profile="urn:example:profile-2"',
diff --git a/tests/test_rdflib_endpoint.py b/tests/test_rdflib_endpoint.py
index db5dafa..7f5cf8d 100644
--- a/tests/test_rdflib_endpoint.py
+++ b/tests/test_rdflib_endpoint.py
@@ -112,6 +112,11 @@ def test_sparql_update(api_key, key_provided, param_method, monkeypatch):
         assert (subject, RDFS.label, Literal("bar")) not in graph
 
 
+def test_sparql_query_update_fail():
+    response = endpoint.post("/", data={"update": label_patch, "query": label_patch})
+    assert response.status_code == 400
+
+
 def test_multiple_accept_return_json():
     response = endpoint.get(
         "/",