diff --git a/gapic/templates/%namespace/%name_%version/%sub/services/%service/_shared_macros.j2 b/gapic/templates/%namespace/%name_%version/%sub/services/%service/_shared_macros.j2
index 6db274e82f..a4d13c34b9 100644
--- a/gapic/templates/%namespace/%name_%version/%sub/services/%service/_shared_macros.j2
+++ b/gapic/templates/%namespace/%name_%version/%sub/services/%service/_shared_macros.j2
@@ -196,8 +196,9 @@ def _get_http_options():
         body_spec (str): The http options body i.e. method.http_options[0].body
         method_name (str): The method name.
         service: The service.
-        is_async (bool): Used to determine the code path i.e. whether for sync or async call. #}
-{% macro rest_call_method_common(body_spec, method_name, service, is_async=False, is_proto_plus_type=False) %}
+        is_async (bool): Used to determine the code path i.e. whether for sync or async call.
+        is_request_message_proto_plus_type (bool): Used to determine whether the request message is a proto-plus type. #}
+{% macro rest_call_method_common(body_spec, method_name, service, is_async=False, is_request_message_proto_plus_type=False) %}
 {% set service_name = service.name %}
 {% set await_prefix = "await " if is_async else "" %}
 {% set async_class_prefix = "Async" if is_async else "" %}
@@ -218,7 +219,7 @@ def _get_http_options():
         request_url = "{host}{uri}".format(host=self._host, uri=transcoded_request['uri'])
         method = transcoded_request['method']
         try:
-            request_payload = {% if is_proto_plus_type %}type(request).to_json(request){% else %}json_format.MessageToJson(request){% endif %}
+            request_payload = {% if is_request_message_proto_plus_type %}type(request).to_json(request){% else %}json_format.MessageToJson(request){% endif %}
 
         except:
             {# TODO(https://github.com/googleapis/gapic-generator-python/issues/2282): Remove try/except and correctly parse request payload. #}
diff --git a/gapic/templates/%namespace/%name_%version/%sub/services/%service/transports/rest.py.j2 b/gapic/templates/%namespace/%name_%version/%sub/services/%service/transports/rest.py.j2
index 95efafb389..0ab91b2974 100644
--- a/gapic/templates/%namespace/%name_%version/%sub/services/%service/transports/rest.py.j2
+++ b/gapic/templates/%namespace/%name_%version/%sub/services/%service/transports/rest.py.j2
@@ -240,7 +240,7 @@ class {{service.name}}RestTransport(_Base{{ service.name }}RestTransport):
             {% endif %}
             """
 
-            {{ shared_macros.rest_call_method_common(body_spec, method.name, service, False, method.output.ident.is_proto_plus_type)|indent(8) }}
+            {{ shared_macros.rest_call_method_common(body_spec, method.name, service, False, method.input.ident.is_proto_plus_type)|indent(8) }}
 
             {% if not method.void %}
             # Return the response
diff --git a/gapic/templates/%namespace/%name_%version/%sub/services/%service/transports/rest_asyncio.py.j2 b/gapic/templates/%namespace/%name_%version/%sub/services/%service/transports/rest_asyncio.py.j2
index 1d6ec87374..10118892d4 100644
--- a/gapic/templates/%namespace/%name_%version/%sub/services/%service/transports/rest_asyncio.py.j2
+++ b/gapic/templates/%namespace/%name_%version/%sub/services/%service/transports/rest_asyncio.py.j2
@@ -202,7 +202,7 @@ class Async{{service.name}}RestTransport(_Base{{ service.name }}RestTransport):
             {% endif %}
             """
 
-            {{ shared_macros.rest_call_method_common(body_spec, method.name, service, True, method.output.ident.is_proto_plus_type)|indent(8) }}
+            {{ shared_macros.rest_call_method_common(body_spec, method.name, service, True, method.input.ident.is_proto_plus_type)|indent(8) }}
 
             {% if not method.void %}
             # Return the response
diff --git a/tests/integration/goldens/asset/google/cloud/asset_v1/services/asset_service/transports/rest.py b/tests/integration/goldens/asset/google/cloud/asset_v1/services/asset_service/transports/rest.py
index b7f32b5fc7..e3a86f49e3 100755
--- a/tests/integration/goldens/asset/google/cloud/asset_v1/services/asset_service/transports/rest.py
+++ b/tests/integration/goldens/asset/google/cloud/asset_v1/services/asset_service/transports/rest.py
@@ -1368,7 +1368,7 @@ def __call__(self,
                 request_url = "{host}{uri}".format(host=self._host, uri=transcoded_request['uri'])
                 method = transcoded_request['method']
                 try:
-                    request_payload = json_format.MessageToJson(request)
+                    request_payload = type(request).to_json(request)
                 except:
                     request_payload = None
                 http_request = {
@@ -2467,7 +2467,7 @@ def __call__(self,
                 request_url = "{host}{uri}".format(host=self._host, uri=transcoded_request['uri'])
                 method = transcoded_request['method']
                 try:
-                    request_payload = json_format.MessageToJson(request)
+                    request_payload = type(request).to_json(request)
                 except:
                     request_payload = None
                 http_request = {
@@ -2552,7 +2552,7 @@ def __call__(self,
                 request_url = "{host}{uri}".format(host=self._host, uri=transcoded_request['uri'])
                 method = transcoded_request['method']
                 try:
-                    request_payload = json_format.MessageToJson(request)
+                    request_payload = type(request).to_json(request)
                 except:
                     request_payload = None
                 http_request = {
@@ -2647,7 +2647,7 @@ def __call__(self,
                 request_url = "{host}{uri}".format(host=self._host, uri=transcoded_request['uri'])
                 method = transcoded_request['method']
                 try:
-                    request_payload = json_format.MessageToJson(request)
+                    request_payload = type(request).to_json(request)
                 except:
                     request_payload = None
                 http_request = {
diff --git a/tests/integration/goldens/eventarc/google/cloud/eventarc_v1/services/eventarc/transports/rest.py b/tests/integration/goldens/eventarc/google/cloud/eventarc_v1/services/eventarc/transports/rest.py
index 1d4a69adf0..dc3ded0df6 100755
--- a/tests/integration/goldens/eventarc/google/cloud/eventarc_v1/services/eventarc/transports/rest.py
+++ b/tests/integration/goldens/eventarc/google/cloud/eventarc_v1/services/eventarc/transports/rest.py
@@ -1286,7 +1286,7 @@ def __call__(self,
                 request_url = "{host}{uri}".format(host=self._host, uri=transcoded_request['uri'])
                 method = transcoded_request['method']
                 try:
-                    request_payload = json_format.MessageToJson(request)
+                    request_payload = type(request).to_json(request)
                 except:
                     request_payload = None
                 http_request = {
@@ -1410,7 +1410,7 @@ def __call__(self,
                 request_url = "{host}{uri}".format(host=self._host, uri=transcoded_request['uri'])
                 method = transcoded_request['method']
                 try:
-                    request_payload = json_format.MessageToJson(request)
+                    request_payload = type(request).to_json(request)
                 except:
                     request_payload = None
                 http_request = {
@@ -1534,7 +1534,7 @@ def __call__(self,
                 request_url = "{host}{uri}".format(host=self._host, uri=transcoded_request['uri'])
                 method = transcoded_request['method']
                 try:
-                    request_payload = json_format.MessageToJson(request)
+                    request_payload = type(request).to_json(request)
                 except:
                     request_payload = None
                 http_request = {
@@ -1655,7 +1655,7 @@ def __call__(self,
                 request_url = "{host}{uri}".format(host=self._host, uri=transcoded_request['uri'])
                 method = transcoded_request['method']
                 try:
-                    request_payload = json_format.MessageToJson(request)
+                    request_payload = type(request).to_json(request)
                 except:
                     request_payload = None
                 http_request = {
@@ -1776,7 +1776,7 @@ def __call__(self,
                 request_url = "{host}{uri}".format(host=self._host, uri=transcoded_request['uri'])
                 method = transcoded_request['method']
                 try:
-                    request_payload = json_format.MessageToJson(request)
+                    request_payload = type(request).to_json(request)
                 except:
                     request_payload = None
                 http_request = {
@@ -1897,7 +1897,7 @@ def __call__(self,
                 request_url = "{host}{uri}".format(host=self._host, uri=transcoded_request['uri'])
                 method = transcoded_request['method']
                 try:
-                    request_payload = json_format.MessageToJson(request)
+                    request_payload = type(request).to_json(request)
                 except:
                     request_payload = None
                 http_request = {
@@ -3130,7 +3130,7 @@ def __call__(self,
                 request_url = "{host}{uri}".format(host=self._host, uri=transcoded_request['uri'])
                 method = transcoded_request['method']
                 try:
-                    request_payload = json_format.MessageToJson(request)
+                    request_payload = type(request).to_json(request)
                 except:
                     request_payload = None
                 http_request = {
@@ -3386,7 +3386,7 @@ def __call__(self,
                 request_url = "{host}{uri}".format(host=self._host, uri=transcoded_request['uri'])
                 method = transcoded_request['method']
                 try:
-                    request_payload = json_format.MessageToJson(request)
+                    request_payload = type(request).to_json(request)
                 except:
                     request_payload = None
                 http_request = {
diff --git a/tests/integration/goldens/redis/google/cloud/redis_v1/services/cloud_redis/transports/rest.py b/tests/integration/goldens/redis/google/cloud/redis_v1/services/cloud_redis/transports/rest.py
index e9a1c7a484..6cf7fb2eca 100755
--- a/tests/integration/goldens/redis/google/cloud/redis_v1/services/cloud_redis/transports/rest.py
+++ b/tests/integration/goldens/redis/google/cloud/redis_v1/services/cloud_redis/transports/rest.py
@@ -952,7 +952,7 @@ def __call__(self,
                 request_url = "{host}{uri}".format(host=self._host, uri=transcoded_request['uri'])
                 method = transcoded_request['method']
                 try:
-                    request_payload = json_format.MessageToJson(request)
+                    request_payload = type(request).to_json(request)
                 except:
                     request_payload = None
                 http_request = {
@@ -1073,7 +1073,7 @@ def __call__(self,
                 request_url = "{host}{uri}".format(host=self._host, uri=transcoded_request['uri'])
                 method = transcoded_request['method']
                 try:
-                    request_payload = json_format.MessageToJson(request)
+                    request_payload = type(request).to_json(request)
                 except:
                     request_payload = None
                 http_request = {
@@ -1197,7 +1197,7 @@ def __call__(self,
                 request_url = "{host}{uri}".format(host=self._host, uri=transcoded_request['uri'])
                 method = transcoded_request['method']
                 try:
-                    request_payload = json_format.MessageToJson(request)
+                    request_payload = type(request).to_json(request)
                 except:
                     request_payload = None
                 http_request = {
@@ -1321,7 +1321,7 @@ def __call__(self,
                 request_url = "{host}{uri}".format(host=self._host, uri=transcoded_request['uri'])
                 method = transcoded_request['method']
                 try:
-                    request_payload = json_format.MessageToJson(request)
+                    request_payload = type(request).to_json(request)
                 except:
                     request_payload = None
                 http_request = {
@@ -1685,7 +1685,7 @@ def __call__(self,
                 request_url = "{host}{uri}".format(host=self._host, uri=transcoded_request['uri'])
                 method = transcoded_request['method']
                 try:
-                    request_payload = json_format.MessageToJson(request)
+                    request_payload = type(request).to_json(request)
                 except:
                     request_payload = None
                 http_request = {
@@ -1931,7 +1931,7 @@ def __call__(self,
                 request_url = "{host}{uri}".format(host=self._host, uri=transcoded_request['uri'])
                 method = transcoded_request['method']
                 try:
-                    request_payload = json_format.MessageToJson(request)
+                    request_payload = type(request).to_json(request)
                 except:
                     request_payload = None
                 http_request = {
@@ -2055,7 +2055,7 @@ def __call__(self,
                 request_url = "{host}{uri}".format(host=self._host, uri=transcoded_request['uri'])
                 method = transcoded_request['method']
                 try:
-                    request_payload = json_format.MessageToJson(request)
+                    request_payload = type(request).to_json(request)
                 except:
                     request_payload = None
                 http_request = {
@@ -2179,7 +2179,7 @@ def __call__(self,
                 request_url = "{host}{uri}".format(host=self._host, uri=transcoded_request['uri'])
                 method = transcoded_request['method']
                 try:
-                    request_payload = json_format.MessageToJson(request)
+                    request_payload = type(request).to_json(request)
                 except:
                     request_payload = None
                 http_request = {
diff --git a/tests/integration/goldens/redis/google/cloud/redis_v1/services/cloud_redis/transports/rest_asyncio.py b/tests/integration/goldens/redis/google/cloud/redis_v1/services/cloud_redis/transports/rest_asyncio.py
index 832be441c1..613a5e3411 100755
--- a/tests/integration/goldens/redis/google/cloud/redis_v1/services/cloud_redis/transports/rest_asyncio.py
+++ b/tests/integration/goldens/redis/google/cloud/redis_v1/services/cloud_redis/transports/rest_asyncio.py
@@ -981,7 +981,7 @@ async def __call__(self,
                 request_url = "{host}{uri}".format(host=self._host, uri=transcoded_request['uri'])
                 method = transcoded_request['method']
                 try:
-                    request_payload = json_format.MessageToJson(request)
+                    request_payload = type(request).to_json(request)
                 except:
                     request_payload = None
                 http_request = {
@@ -1108,7 +1108,7 @@ async def __call__(self,
                 request_url = "{host}{uri}".format(host=self._host, uri=transcoded_request['uri'])
                 method = transcoded_request['method']
                 try:
-                    request_payload = json_format.MessageToJson(request)
+                    request_payload = type(request).to_json(request)
                 except:
                     request_payload = None
                 http_request = {
@@ -1238,7 +1238,7 @@ async def __call__(self,
                 request_url = "{host}{uri}".format(host=self._host, uri=transcoded_request['uri'])
                 method = transcoded_request['method']
                 try:
-                    request_payload = json_format.MessageToJson(request)
+                    request_payload = type(request).to_json(request)
                 except:
                     request_payload = None
                 http_request = {
@@ -1368,7 +1368,7 @@ async def __call__(self,
                 request_url = "{host}{uri}".format(host=self._host, uri=transcoded_request['uri'])
                 method = transcoded_request['method']
                 try:
-                    request_payload = json_format.MessageToJson(request)
+                    request_payload = type(request).to_json(request)
                 except:
                     request_payload = None
                 http_request = {
@@ -1746,7 +1746,7 @@ async def __call__(self,
                 request_url = "{host}{uri}".format(host=self._host, uri=transcoded_request['uri'])
                 method = transcoded_request['method']
                 try:
-                    request_payload = json_format.MessageToJson(request)
+                    request_payload = type(request).to_json(request)
                 except:
                     request_payload = None
                 http_request = {
@@ -2002,7 +2002,7 @@ async def __call__(self,
                 request_url = "{host}{uri}".format(host=self._host, uri=transcoded_request['uri'])
                 method = transcoded_request['method']
                 try:
-                    request_payload = json_format.MessageToJson(request)
+                    request_payload = type(request).to_json(request)
                 except:
                     request_payload = None
                 http_request = {
@@ -2132,7 +2132,7 @@ async def __call__(self,
                 request_url = "{host}{uri}".format(host=self._host, uri=transcoded_request['uri'])
                 method = transcoded_request['method']
                 try:
-                    request_payload = json_format.MessageToJson(request)
+                    request_payload = type(request).to_json(request)
                 except:
                     request_payload = None
                 http_request = {
@@ -2262,7 +2262,7 @@ async def __call__(self,
                 request_url = "{host}{uri}".format(host=self._host, uri=transcoded_request['uri'])
                 method = transcoded_request['method']
                 try:
-                    request_payload = json_format.MessageToJson(request)
+                    request_payload = type(request).to_json(request)
                 except:
                     request_payload = None
                 http_request = {
diff --git a/tests/integration/goldens/redis_selective/google/cloud/redis_v1/services/cloud_redis/transports/rest.py b/tests/integration/goldens/redis_selective/google/cloud/redis_v1/services/cloud_redis/transports/rest.py
index 7e43d25df4..2bcbb50899 100755
--- a/tests/integration/goldens/redis_selective/google/cloud/redis_v1/services/cloud_redis/transports/rest.py
+++ b/tests/integration/goldens/redis_selective/google/cloud/redis_v1/services/cloud_redis/transports/rest.py
@@ -688,7 +688,7 @@ def __call__(self,
                 request_url = "{host}{uri}".format(host=self._host, uri=transcoded_request['uri'])
                 method = transcoded_request['method']
                 try:
-                    request_payload = json_format.MessageToJson(request)
+                    request_payload = type(request).to_json(request)
                 except:
                     request_payload = None
                 http_request = {
@@ -809,7 +809,7 @@ def __call__(self,
                 request_url = "{host}{uri}".format(host=self._host, uri=transcoded_request['uri'])
                 method = transcoded_request['method']
                 try:
-                    request_payload = json_format.MessageToJson(request)
+                    request_payload = type(request).to_json(request)
                 except:
                     request_payload = None
                 http_request = {
@@ -1175,7 +1175,7 @@ def __call__(self,
                 request_url = "{host}{uri}".format(host=self._host, uri=transcoded_request['uri'])
                 method = transcoded_request['method']
                 try:
-                    request_payload = json_format.MessageToJson(request)
+                    request_payload = type(request).to_json(request)
                 except:
                     request_payload = None
                 http_request = {
diff --git a/tests/integration/goldens/redis_selective/google/cloud/redis_v1/services/cloud_redis/transports/rest_asyncio.py b/tests/integration/goldens/redis_selective/google/cloud/redis_v1/services/cloud_redis/transports/rest_asyncio.py
index fdb993eada..5127f0d171 100755
--- a/tests/integration/goldens/redis_selective/google/cloud/redis_v1/services/cloud_redis/transports/rest_asyncio.py
+++ b/tests/integration/goldens/redis_selective/google/cloud/redis_v1/services/cloud_redis/transports/rest_asyncio.py
@@ -687,7 +687,7 @@ async def __call__(self,
                 request_url = "{host}{uri}".format(host=self._host, uri=transcoded_request['uri'])
                 method = transcoded_request['method']
                 try:
-                    request_payload = json_format.MessageToJson(request)
+                    request_payload = type(request).to_json(request)
                 except:
                     request_payload = None
                 http_request = {
@@ -814,7 +814,7 @@ async def __call__(self,
                 request_url = "{host}{uri}".format(host=self._host, uri=transcoded_request['uri'])
                 method = transcoded_request['method']
                 try:
-                    request_payload = json_format.MessageToJson(request)
+                    request_payload = type(request).to_json(request)
                 except:
                     request_payload = None
                 http_request = {
@@ -1194,7 +1194,7 @@ async def __call__(self,
                 request_url = "{host}{uri}".format(host=self._host, uri=transcoded_request['uri'])
                 method = transcoded_request['method']
                 try:
-                    request_payload = json_format.MessageToJson(request)
+                    request_payload = type(request).to_json(request)
                 except:
                     request_payload = None
                 http_request = {