diff --git a/gql/client.py b/gql/client.py
index a79d4b72..0d9e36c7 100644
--- a/gql/client.py
+++ b/gql/client.py
@@ -106,7 +106,7 @@ def __init__(
         :param serialize_variables: whether the variable values should be
             serialized. Used for custom scalars and/or enums. Default: False.
         :param parse_results: Whether gql will try to parse the serialized output
-                sent by the backend. Can be used to unserialize custom scalars or enums.
+                sent by the backend. Can be used to deserialize custom scalars or enums.
         :param batch_interval: Time to wait in seconds for batching requests together.
                 Batching is disabled (by default) if 0.
         :param batch_max: Maximum number of requests in a single batch.
@@ -892,7 +892,7 @@ def _execute(
         :param serialize_variables: whether the variable values should be
             serialized. Used for custom scalars and/or enums.
             By default use the serialize_variables argument of the client.
-        :param parse_result: Whether gql will unserialize the result.
+        :param parse_result: Whether gql will deserialize the result.
             By default use the parse_results argument of the client.
 
         The extra arguments are passed to the transport execute method."""
@@ -1006,7 +1006,7 @@ def execute(
         :param serialize_variables: whether the variable values should be
             serialized. Used for custom scalars and/or enums.
             By default use the serialize_variables argument of the client.
-        :param parse_result: Whether gql will unserialize the result.
+        :param parse_result: Whether gql will deserialize the result.
             By default use the parse_results argument of the client.
         :param get_execution_result: return the full ExecutionResult instance instead of
             only the "data" field. Necessary if you want to get the "extensions" field.
@@ -1057,7 +1057,7 @@ def _execute_batch(
         :param serialize_variables: whether the variable values should be
             serialized. Used for custom scalars and/or enums.
             By default use the serialize_variables argument of the client.
-        :param parse_result: Whether gql will unserialize the result.
+        :param parse_result: Whether gql will deserialize the result.
             By default use the parse_results argument of the client.
         :param validate_document: Whether we still need to validate the document.
 
@@ -1151,7 +1151,7 @@ def execute_batch(
         :param serialize_variables: whether the variable values should be
             serialized. Used for custom scalars and/or enums.
             By default use the serialize_variables argument of the client.
-        :param parse_result: Whether gql will unserialize the result.
+        :param parse_result: Whether gql will deserialize the result.
             By default use the parse_results argument of the client.
         :param get_execution_result: return the full ExecutionResult instance instead of
             only the "data" field. Necessary if you want to get the "extensions" field.
@@ -1333,7 +1333,7 @@ async def _subscribe(
         :param serialize_variables: whether the variable values should be
             serialized. Used for custom scalars and/or enums.
             By default use the serialize_variables argument of the client.
-        :param parse_result: Whether gql will unserialize the result.
+        :param parse_result: Whether gql will deserialize the result.
             By default use the parse_results argument of the client.
 
         The extra arguments are passed to the transport subscribe method."""
@@ -1454,7 +1454,7 @@ async def subscribe(
         :param serialize_variables: whether the variable values should be
             serialized. Used for custom scalars and/or enums.
             By default use the serialize_variables argument of the client.
-        :param parse_result: Whether gql will unserialize the result.
+        :param parse_result: Whether gql will deserialize the result.
             By default use the parse_results argument of the client.
         :param get_execution_result: yield the full ExecutionResult instance instead of
             only the "data" field. Necessary if you want to get the "extensions" field.
@@ -1511,7 +1511,7 @@ async def _execute(
         :param serialize_variables: whether the variable values should be
             serialized. Used for custom scalars and/or enums.
             By default use the serialize_variables argument of the client.
-        :param parse_result: Whether gql will unserialize the result.
+        :param parse_result: Whether gql will deserialize the result.
             By default use the parse_results argument of the client.
 
         The extra arguments are passed to the transport execute method."""
@@ -1617,7 +1617,7 @@ async def execute(
         :param serialize_variables: whether the variable values should be
             serialized. Used for custom scalars and/or enums.
             By default use the serialize_variables argument of the client.
-        :param parse_result: Whether gql will unserialize the result.
+        :param parse_result: Whether gql will deserialize the result.
             By default use the parse_results argument of the client.
         :param get_execution_result: return the full ExecutionResult instance instead of
             only the "data" field. Necessary if you want to get the "extensions" field.
diff --git a/gql/transport/aiohttp.py b/gql/transport/aiohttp.py
index 60f42c94..be22ce9c 100644
--- a/gql/transport/aiohttp.py
+++ b/gql/transport/aiohttp.py
@@ -50,6 +50,7 @@ def __init__(
         timeout: Optional[int] = None,
         ssl_close_timeout: Optional[Union[int, float]] = 10,
         json_serialize: Callable = json.dumps,
+        json_deserialize: Callable = json.loads,
         client_session_args: Optional[Dict[str, Any]] = None,
     ) -> None:
         """Initialize the transport with the given aiohttp parameters.
@@ -64,6 +65,8 @@ def __init__(
                                   to close properly
         :param json_serialize: Json serializer callable.
                 By default json.dumps() function
+        :param json_deserialize: Json deserializer callable.
+                By default json.loads() function
         :param client_session_args: Dict of extra args passed to
                 `aiohttp.ClientSession`_
 
@@ -81,6 +84,7 @@ def __init__(
         self.session: Optional[aiohttp.ClientSession] = None
         self.response_headers: Optional[CIMultiDictProxy[str]]
         self.json_serialize: Callable = json_serialize
+        self.json_deserialize: Callable = json_deserialize
 
     async def connect(self) -> None:
         """Coroutine which will create an aiohttp ClientSession() as self.session.
@@ -328,7 +332,7 @@ async def raise_response_error(resp: aiohttp.ClientResponse, reason: str):
                 )
 
             try:
-                result = await resp.json(content_type=None)
+                result = await resp.json(loads=self.json_deserialize, content_type=None)
 
                 if log.isEnabledFor(logging.INFO):
                     result_text = await resp.text()
diff --git a/gql/transport/httpx.py b/gql/transport/httpx.py
index cfc25dc9..811601b8 100644
--- a/gql/transport/httpx.py
+++ b/gql/transport/httpx.py
@@ -38,6 +38,7 @@ def __init__(
         self,
         url: Union[str, httpx.URL],
         json_serialize: Callable = json.dumps,
+        json_deserialize: Callable = json.loads,
         **kwargs,
     ):
         """Initialize the transport with the given httpx parameters.
@@ -45,10 +46,13 @@ def __init__(
         :param url: The GraphQL server URL. Example: 'https://server.com:PORT/path'.
         :param json_serialize: Json serializer callable.
                 By default json.dumps() function.
+        :param json_deserialize: Json deserializer callable.
+                By default json.loads() function.
         :param kwargs: Extra args passed to the `httpx` client.
         """
         self.url = url
         self.json_serialize = json_serialize
+        self.json_deserialize = json_deserialize
         self.kwargs = kwargs
 
     def _prepare_request(
@@ -145,7 +149,7 @@ def _prepare_result(self, response: httpx.Response) -> ExecutionResult:
             log.debug("<<< %s", response.text)
 
         try:
-            result: Dict[str, Any] = response.json()
+            result: Dict[str, Any] = self.json_deserialize(response.content)
 
         except Exception:
             self._raise_response_error(response, "Not a JSON answer")
diff --git a/tests/test_aiohttp.py b/tests/test_aiohttp.py
index 09259e51..b16964d0 100644
--- a/tests/test_aiohttp.py
+++ b/tests/test_aiohttp.py
@@ -1511,6 +1511,56 @@ async def handler(request):
     assert expected_log in caplog.text
 
 
+query_float_str = """
+    query getPi {
+      pi
+    }
+"""
+
+query_float_server_answer_data = '{"pi": 3.141592653589793238462643383279502884197}'
+
+query_float_server_answer = f'{{"data":{query_float_server_answer_data}}}'
+
+
+@pytest.mark.asyncio
+async def test_aiohttp_json_deserializer(event_loop, aiohttp_server):
+    from aiohttp import web
+    from decimal import Decimal
+    from functools import partial
+    from gql.transport.aiohttp import AIOHTTPTransport
+
+    async def handler(request):
+        return web.Response(
+            text=query_float_server_answer,
+            content_type="application/json",
+        )
+
+    app = web.Application()
+    app.router.add_route("POST", "/", handler)
+    server = await aiohttp_server(app)
+
+    url = server.make_url("/")
+
+    json_loads = partial(json.loads, parse_float=Decimal)
+
+    transport = AIOHTTPTransport(
+        url=url,
+        timeout=10,
+        json_deserialize=json_loads,
+    )
+
+    async with Client(transport=transport) as session:
+
+        query = gql(query_float_str)
+
+        # Execute query asynchronously
+        result = await session.execute(query)
+
+        pi = result["pi"]
+
+        assert pi == Decimal("3.141592653589793238462643383279502884197")
+
+
 @pytest.mark.asyncio
 async def test_aiohttp_connector_owner_false(event_loop, aiohttp_server):
     from aiohttp import web, TCPConnector
diff --git a/tests/test_httpx_async.py b/tests/test_httpx_async.py
index e5be73ec..3665f5d8 100644
--- a/tests/test_httpx_async.py
+++ b/tests/test_httpx_async.py
@@ -1389,3 +1389,54 @@ async def handler(request):
     # Checking that there is no space after the colon in the log
     expected_log = '"query":"query getContinents'
     assert expected_log in caplog.text
+
+
+query_float_str = """
+    query getPi {
+      pi
+    }
+"""
+
+query_float_server_answer_data = '{"pi": 3.141592653589793238462643383279502884197}'
+
+query_float_server_answer = f'{{"data":{query_float_server_answer_data}}}'
+
+
+@pytest.mark.aiohttp
+@pytest.mark.asyncio
+async def test_httpx_json_deserializer(event_loop, aiohttp_server):
+    from aiohttp import web
+    from decimal import Decimal
+    from functools import partial
+    from gql.transport.httpx import HTTPXAsyncTransport
+
+    async def handler(request):
+        return web.Response(
+            text=query_float_server_answer,
+            content_type="application/json",
+        )
+
+    app = web.Application()
+    app.router.add_route("POST", "/", handler)
+    server = await aiohttp_server(app)
+
+    url = str(server.make_url("/"))
+
+    json_loads = partial(json.loads, parse_float=Decimal)
+
+    transport = HTTPXAsyncTransport(
+        url=url,
+        timeout=10,
+        json_deserialize=json_loads,
+    )
+
+    async with Client(transport=transport) as session:
+
+        query = gql(query_float_str)
+
+        # Execute query asynchronously
+        result = await session.execute(query)
+
+        pi = result["pi"]
+
+        assert pi == Decimal("3.141592653589793238462643383279502884197")