diff --git a/gql/dsl.py b/gql/dsl.py
index 6407f267..80361240 100644
--- a/gql/dsl.py
+++ b/gql/dsl.py
@@ -84,7 +84,7 @@ def select(self, *fields):
         added_selections = selections(*fields)
         if selection_set:
             selection_set.selections = FrozenList(
-                selection_set.selections + added_selections
+                selection_set.selections + list(added_selections)
             )
         else:
             self.ast_field.selection_set = SelectionSetNode(
diff --git a/gql/transport/local_schema.py b/gql/transport/local_schema.py
index 54d71613..18cd2982 100644
--- a/gql/transport/local_schema.py
+++ b/gql/transport/local_schema.py
@@ -1,5 +1,5 @@
 from inspect import isawaitable
-from typing import Any, AsyncGenerator, AsyncIterator, Awaitable, Coroutine, cast
+from typing import AsyncGenerator, Awaitable, cast
 
 from graphql import DocumentNode, ExecutionResult, GraphQLSchema, execute, subscribe
 
@@ -50,27 +50,16 @@ async def execute(
     async def subscribe(
         self, document: DocumentNode, *args, **kwargs,
     ) -> AsyncGenerator[ExecutionResult, None]:
-        """Send a query and receive the results using an async generator
-
-        The query can be a graphql query, mutation or subscription
+        """Send a subscription and receive the results using an async generator
 
         The results are sent as an ExecutionResult object
         """
 
-        subscribe_result = subscribe(self.schema, document, *args, **kwargs)
+        subscribe_result = await subscribe(self.schema, document, *args, **kwargs)
 
         if isinstance(subscribe_result, ExecutionResult):
-            yield ExecutionResult
+            yield subscribe_result
 
         else:
-            # if we don't get an ExecutionResult, then we should receive
-            # a Coroutine returning an AsyncIterator[ExecutionResult]
-
-            subscribe_coro = cast(
-                Coroutine[Any, Any, AsyncIterator[ExecutionResult]], subscribe_result
-            )
-
-            subscribe_generator = await subscribe_coro
-
-            async for result in subscribe_generator:
+            async for result in subscribe_result:
                 yield result
diff --git a/gql/transport/transport.py b/gql/transport/transport.py
index 05bb063c..56d882f4 100644
--- a/gql/transport/transport.py
+++ b/gql/transport/transport.py
@@ -20,7 +20,7 @@ def execute(self, document: DocumentNode, *args, **kwargs) -> ExecutionResult:
     def connect(self):
         """Establish a session with the transport.
         """
-        pass
+        pass  # pragma: no cover
 
     def close(self):
         """Close the transport
diff --git a/tests/starwars/fixtures.py b/tests/starwars/fixtures.py
index 409ca1bd..7bc31037 100644
--- a/tests/starwars/fixtures.py
+++ b/tests/starwars/fixtures.py
@@ -1,3 +1,4 @@
+import asyncio
 from collections import namedtuple
 
 Human = namedtuple("Human", "id name friends appearsIn homePlanet")
@@ -94,6 +95,11 @@ def getHero(episode):
     return artoo
 
 
+async def getHeroAsync(episode):
+    await asyncio.sleep(0.001)
+    return getHero(episode)
+
+
 def getHuman(id):
     return humanData.get(id)
 
diff --git a/tests/starwars/schema.py b/tests/starwars/schema.py
index e23822f3..95320ffe 100644
--- a/tests/starwars/schema.py
+++ b/tests/starwars/schema.py
@@ -24,7 +24,7 @@
     getCharacters,
     getDroid,
     getFriends,
-    getHero,
+    getHeroAsync,
     getHuman,
     reviews,
 )
@@ -146,7 +146,7 @@
                     type_=episodeEnum,  # type: ignore
                 )
             },
-            resolve=lambda root, info, **args: getHero(args.get("episode")),
+            resolve=lambda root, info, **args: getHeroAsync(args.get("episode")),
         ),
         "human": GraphQLField(
             humanType,
diff --git a/tests/starwars/test_dsl.py b/tests/starwars/test_dsl.py
index 7501e84f..9047f352 100644
--- a/tests/starwars/test_dsl.py
+++ b/tests/starwars/test_dsl.py
@@ -53,6 +53,18 @@ def test_hero_name_and_friends_query(ds):
     assert query == str(query_dsl)
 
 
+def test_hero_id_and_name(ds):
+    query = """
+hero {
+  id
+  name
+}
+    """.strip()
+    query_dsl = ds.Query.hero.select(ds.Character.id)
+    query_dsl = query_dsl.select(ds.Character.name)
+    assert query == str(query_dsl)
+
+
 def test_nested_query(ds):
     query = """
 hero {
diff --git a/tests/starwars/test_subscription.py b/tests/starwars/test_subscription.py
index 7a76b3bf..3753ab2f 100644
--- a/tests/starwars/test_subscription.py
+++ b/tests/starwars/test_subscription.py
@@ -1,5 +1,5 @@
 import pytest
-from graphql import subscribe
+from graphql import ExecutionResult, GraphQLError, subscribe
 
 from gql import Client, gql
 
@@ -57,3 +57,38 @@ async def test_subscription_support_using_client():
         ]
 
     assert results == expected
+
+
+subscription_invalid_str = """
+    subscription ListenEpisodeReviews($ep: Episode!) {
+      qsdfqsdfqsdf
+    }
+"""
+
+
+@pytest.mark.asyncio
+async def test_subscription_support_using_client_invalid_field():
+
+    subs = gql(subscription_invalid_str)
+
+    params = {"ep": "JEDI"}
+
+    async with Client(schema=StarWarsSchema) as session:
+
+        # We subscribe directly from the transport to avoid local validation
+        results = [
+            result
+            async for result in session.transport.subscribe(
+                subs, variable_values=params
+            )
+        ]
+
+    assert len(results) == 1
+    result = results[0]
+    assert isinstance(result, ExecutionResult)
+    assert result.data is None
+    assert isinstance(result.errors, list)
+    assert len(result.errors) == 1
+    error = result.errors[0]
+    assert isinstance(error, GraphQLError)
+    assert error.message == "The subscription field 'qsdfqsdfqsdf' is not defined."