diff --git a/tests/oauth2/test_service_account.py b/tests/oauth2/test_service_account.py
index 40a4ca2..648541e 100644
--- a/tests/oauth2/test_service_account.py
+++ b/tests/oauth2/test_service_account.py
@@ -203,18 +203,18 @@
         assert "x-goog-user-project" not in headers
         assert "token" in headers["authorization"]
 
-    @mock.patch("google.auth.jwt.Credentials.from_signing_credentials", autospec=True)
-    def test__create_self_signed_jwt(self, from_signing_credentials):
+    @mock.patch("google.auth.jwt.Credentials", instance=True, autospec=True)
+    def test__create_self_signed_jwt(self, jwt):
         credentials = service_account.Credentials(
             SIGNER, self.SERVICE_ACCOUNT_EMAIL, self.TOKEN_URI
         )
 
         audience = "https://pubsub.googleapis.com"
         credentials._create_self_signed_jwt(audience)
-        from_signing_credentials.assert_called_once_with(credentials, audience)
+        jwt.from_signing_credentials.assert_called_once_with(credentials, audience)
 
-    @mock.patch("google.auth.jwt.Credentials.from_signing_credentials", autospec=True)
-    def test__create_self_signed_jwt_with_user_scopes(self, from_signing_credentials):
+    @mock.patch("google.auth.jwt.Credentials", instance=True, autospec=True)
+    def test__create_self_signed_jwt_with_user_scopes(self, jwt):
         credentials = service_account.Credentials(
             SIGNER, self.SERVICE_ACCOUNT_EMAIL, self.TOKEN_URI, scopes=["foo"]
         )
@@ -223,7 +223,7 @@
         credentials._create_self_signed_jwt(audience)
 
         # JWT should not be created if there are user-defined scopes
-        from_signing_credentials.assert_not_called()
+        jwt.from_signing_credentials.assert_not_called()
 
     @mock.patch("google.oauth2._client.jwt_grant", autospec=True)
     def test_refresh_success(self, jwt_grant):
diff --git a/tests/oauth2/test_sts.py b/tests/oauth2/test_sts.py
index 8792bd6..e8e008d 100644
--- a/tests/oauth2/test_sts.py
+++ b/tests/oauth2/test_sts.py
@@ -128,7 +128,7 @@
             self.ADDON_HEADERS,
         )
 
-        self.assert_request_kwargs(request.call_args.kwargs, headers, request_data)
+        self.assert_request_kwargs(request.call_args[1], headers, request_data)
         assert response == self.SUCCESS_RESPONSE
 
     def test_exchange_token_partial_success_without_auth(self):
@@ -157,7 +157,7 @@
             requested_token_type=self.REQUESTED_TOKEN_TYPE,
         )
 
-        self.assert_request_kwargs(request.call_args.kwargs, headers, request_data)
+        self.assert_request_kwargs(request.call_args[1], headers, request_data)
         assert response == self.SUCCESS_RESPONSE
 
     def test_exchange_token_non200_without_auth(self):
@@ -227,7 +227,7 @@
             self.ADDON_HEADERS,
         )
 
-        self.assert_request_kwargs(request.call_args.kwargs, headers, request_data)
+        self.assert_request_kwargs(request.call_args[1], headers, request_data)
         assert response == self.SUCCESS_RESPONSE
 
     def test_exchange_token_partial_success_with_basic_auth(self):
@@ -259,7 +259,7 @@
             requested_token_type=self.REQUESTED_TOKEN_TYPE,
         )
 
-        self.assert_request_kwargs(request.call_args.kwargs, headers, request_data)
+        self.assert_request_kwargs(request.call_args[1], headers, request_data)
         assert response == self.SUCCESS_RESPONSE
 
     def test_exchange_token_non200_with_basic_auth(self):
@@ -331,7 +331,7 @@
             self.ADDON_HEADERS,
         )
 
-        self.assert_request_kwargs(request.call_args.kwargs, headers, request_data)
+        self.assert_request_kwargs(request.call_args[1], headers, request_data)
         assert response == self.SUCCESS_RESPONSE
 
     def test_exchange_token_partial_success_with_reqbody_auth(self):
@@ -362,7 +362,7 @@
             requested_token_type=self.REQUESTED_TOKEN_TYPE,
         )
 
-        self.assert_request_kwargs(request.call_args.kwargs, headers, request_data)
+        self.assert_request_kwargs(request.call_args[1], headers, request_data)
         assert response == self.SUCCESS_RESPONSE
 
     def test_exchange_token_non200_with_reqbody_auth(self):
diff --git a/tests/test_aws.py b/tests/test_aws.py
index 9a8f98e..7a55841 100644
--- a/tests/test_aws.py
+++ b/tests/test_aws.py
@@ -959,15 +959,15 @@
         )
         # Assert region request.
         self.assert_aws_metadata_request_kwargs(
-            request.call_args_list[0].kwargs, REGION_URL
+            request.call_args_list[0][1], REGION_URL
         )
         # Assert role request.
         self.assert_aws_metadata_request_kwargs(
-            request.call_args_list[1].kwargs, SECURITY_CREDS_URL
+            request.call_args_list[1][1], SECURITY_CREDS_URL
         )
         # Assert security credentials request.
         self.assert_aws_metadata_request_kwargs(
-            request.call_args_list[2].kwargs,
+            request.call_args_list[2][1],
             "{}/{}".format(SECURITY_CREDS_URL, self.AWS_ROLE),
             {"Content-Type": "application/json"},
         )
@@ -986,11 +986,11 @@
         assert len(new_request.call_args_list) == 2
         # Assert role request.
         self.assert_aws_metadata_request_kwargs(
-            new_request.call_args_list[0].kwargs, SECURITY_CREDS_URL
+            new_request.call_args_list[0][1], SECURITY_CREDS_URL
         )
         # Assert security credentials request.
         self.assert_aws_metadata_request_kwargs(
-            new_request.call_args_list[1].kwargs,
+            new_request.call_args_list[1][1],
             "{}/{}".format(SECURITY_CREDS_URL, self.AWS_ROLE),
             {"Content-Type": "application/json"},
         )
@@ -1193,7 +1193,7 @@
         assert len(request.call_args_list) == 4
         # Fourth request should be sent to GCP STS endpoint.
         self.assert_token_request_kwargs(
-            request.call_args_list[3].kwargs, token_headers, token_request_data
+            request.call_args_list[3][1], token_headers, token_request_data
         )
         assert credentials.token == self.SUCCESS_RESPONSE["access_token"]
         assert credentials.quota_project_id == QUOTA_PROJECT_ID
@@ -1249,7 +1249,7 @@
         assert len(request.call_args_list) == 4
         # Fourth request should be sent to GCP STS endpoint.
         self.assert_token_request_kwargs(
-            request.call_args_list[3].kwargs, token_headers, token_request_data
+            request.call_args_list[3][1], token_headers, token_request_data
         )
         assert credentials.token == self.SUCCESS_RESPONSE["access_token"]
         assert credentials.quota_project_id == QUOTA_PROJECT_ID
@@ -1326,12 +1326,12 @@
         assert len(request.call_args_list) == 5
         # Fourth request should be sent to GCP STS endpoint.
         self.assert_token_request_kwargs(
-            request.call_args_list[3].kwargs, token_headers, token_request_data
+            request.call_args_list[3][1], token_headers, token_request_data
         )
         # Fifth request should be sent to iamcredentials endpoint for service
         # account impersonation.
         self.assert_impersonation_request_kwargs(
-            request.call_args_list[4].kwargs,
+            request.call_args_list[4][1],
             impersonation_headers,
             impersonation_request_data,
         )
@@ -1410,12 +1410,12 @@
         assert len(request.call_args_list) == 5
         # Fourth request should be sent to GCP STS endpoint.
         self.assert_token_request_kwargs(
-            request.call_args_list[3].kwargs, token_headers, token_request_data
+            request.call_args_list[3][1], token_headers, token_request_data
         )
         # Fifth request should be sent to iamcredentials endpoint for service
         # account impersonation.
         self.assert_impersonation_request_kwargs(
-            request.call_args_list[4].kwargs,
+            request.call_args_list[4][1],
             impersonation_headers,
             impersonation_request_data,
         )
diff --git a/tests/test_external_account.py b/tests/test_external_account.py
index 42e53ec..8f8d980 100644
--- a/tests/test_external_account.py
+++ b/tests/test_external_account.py
@@ -363,9 +363,7 @@
 
         credentials.refresh(request)
 
-        self.assert_token_request_kwargs(
-            request.call_args.kwargs, headers, request_data
-        )
+        self.assert_token_request_kwargs(request.call_args[1], headers, request_data)
         assert credentials.valid
         assert credentials.expiry == expected_expiry
         assert not credentials.expired
@@ -422,11 +420,11 @@
         assert len(request.call_args_list) == 2
         # Verify token exchange request parameters.
         self.assert_token_request_kwargs(
-            request.call_args_list[0].kwargs, token_headers, token_request_data
+            request.call_args_list[0][1], token_headers, token_request_data
         )
         # Verify service account impersonation request parameters.
         self.assert_impersonation_request_kwargs(
-            request.call_args_list[1].kwargs,
+            request.call_args_list[1][1],
             impersonation_headers,
             impersonation_request_data,
         )
@@ -436,7 +434,7 @@
         assert credentials.token == impersonation_response["accessToken"]
 
     def test_refresh_without_client_auth_success_explicit_user_scopes_ignore_default_scopes(
-        self
+        self,
     ):
         headers = {"Content-Type": "application/x-www-form-urlencoded"}
         request_data = {
@@ -458,9 +456,7 @@
 
         credentials.refresh(request)
 
-        self.assert_token_request_kwargs(
-            request.call_args.kwargs, headers, request_data
-        )
+        self.assert_token_request_kwargs(request.call_args[1], headers, request_data)
         assert credentials.valid
         assert not credentials.expired
         assert credentials.token == self.SUCCESS_RESPONSE["access_token"]
@@ -488,9 +484,7 @@
 
         credentials.refresh(request)
 
-        self.assert_token_request_kwargs(
-            request.call_args.kwargs, headers, request_data
-        )
+        self.assert_token_request_kwargs(request.call_args[1], headers, request_data)
         assert credentials.valid
         assert not credentials.expired
         assert credentials.token == self.SUCCESS_RESPONSE["access_token"]
@@ -551,9 +545,7 @@
 
         credentials.refresh(request)
 
-        self.assert_token_request_kwargs(
-            request.call_args.kwargs, headers, request_data
-        )
+        self.assert_token_request_kwargs(request.call_args[1], headers, request_data)
         assert credentials.valid
         assert not credentials.expired
         assert credentials.token == self.SUCCESS_RESPONSE["access_token"]
@@ -616,11 +608,11 @@
         assert len(request.call_args_list) == 2
         # Verify token exchange request parameters.
         self.assert_token_request_kwargs(
-            request.call_args_list[0].kwargs, token_headers, token_request_data
+            request.call_args_list[0][1], token_headers, token_request_data
         )
         # Verify service account impersonation request parameters.
         self.assert_impersonation_request_kwargs(
-            request.call_args_list[1].kwargs,
+            request.call_args_list[1][1],
             impersonation_headers,
             impersonation_request_data,
         )
@@ -687,11 +679,11 @@
         assert len(request.call_args_list) == 2
         # Verify token exchange request parameters.
         self.assert_token_request_kwargs(
-            request.call_args_list[0].kwargs, token_headers, token_request_data
+            request.call_args_list[0][1], token_headers, token_request_data
         )
         # Verify service account impersonation request parameters.
         self.assert_impersonation_request_kwargs(
-            request.call_args_list[1].kwargs,
+            request.call_args_list[1][1],
             impersonation_headers,
             impersonation_request_data,
         )
@@ -1045,11 +1037,11 @@
         assert len(request.call_args_list) == 3
         # Verify token exchange request parameters.
         self.assert_token_request_kwargs(
-            request.call_args_list[0].kwargs, token_headers, token_request_data
+            request.call_args_list[0][1], token_headers, token_request_data
         )
         # Verify service account impersonation request parameters.
         self.assert_impersonation_request_kwargs(
-            request.call_args_list[1].kwargs,
+            request.call_args_list[1][1],
             impersonation_headers,
             impersonation_request_data,
         )
@@ -1061,7 +1053,7 @@
         assert credentials.token == impersonation_response["accessToken"]
         # Verify cloud resource manager request parameters.
         self.assert_resource_manager_request_kwargs(
-            request.call_args_list[2].kwargs,
+            request.call_args_list[2][1],
             self.PROJECT_NUMBER,
             {
                 "x-goog-user-project": self.QUOTA_PROJECT_ID,
diff --git a/tests/test_iam.py b/tests/test_iam.py
index fbd3e41..382713b 100644
--- a/tests/test_iam.py
+++ b/tests/test_iam.py
@@ -89,7 +89,7 @@
         returned_signature = signer.sign("123")
 
         assert returned_signature == signature
-        kwargs = request.call_args.kwargs
+        kwargs = request.call_args[1]
         assert kwargs["headers"]["Content-Type"] == "application/json"
 
     def test_sign_bytes_failure(self):
diff --git a/tests/test_identity_pool.py b/tests/test_identity_pool.py
index c017ab5..90a0e25 100644
--- a/tests/test_identity_pool.py
+++ b/tests/test_identity_pool.py
@@ -223,10 +223,10 @@
 
         assert len(request.call_args_list) == len(requests)
         if credential_data:
-            cls.assert_credential_request_kwargs(request.call_args_list[0].kwargs, None)
+            cls.assert_credential_request_kwargs(request.call_args_list[0][1], None)
         # Verify token exchange request parameters.
         cls.assert_token_request_kwargs(
-            request.call_args_list[token_request_index].kwargs,
+            request.call_args_list[token_request_index][1],
             token_headers,
             token_request_data,
             token_url,
@@ -235,7 +235,7 @@
         # is processed.
         if service_account_impersonation_url:
             cls.assert_impersonation_request_kwargs(
-                request.call_args_list[impersonation_request_index].kwargs,
+                request.call_args_list[impersonation_request_index][1],
                 impersonation_headers,
                 impersonation_request_data,
                 service_account_impersonation_url,
@@ -505,7 +505,7 @@
         assert excinfo.match(r"File './not_found.txt' was not found")
 
     def test_refresh_text_file_success_without_impersonation_ignore_default_scopes(
-        self
+        self,
     ):
         credentials = self.make_credentials(
             client_id=CLIENT_ID,
@@ -677,7 +677,7 @@
         subject_token = credentials.retrieve_subject_token(request)
 
         assert subject_token == TEXT_FILE_SUBJECT_TOKEN
-        self.assert_credential_request_kwargs(request.call_args_list[0].kwargs, None)
+        self.assert_credential_request_kwargs(request.call_args_list[0][1], None)
 
     def test_retrieve_subject_token_from_url_with_headers(self):
         credentials = self.make_credentials(
@@ -688,7 +688,7 @@
 
         assert subject_token == TEXT_FILE_SUBJECT_TOKEN
         self.assert_credential_request_kwargs(
-            request.call_args_list[0].kwargs, {"foo": "bar"}
+            request.call_args_list[0][1], {"foo": "bar"}
         )
 
     def test_retrieve_subject_token_from_url_json(self):
@@ -699,7 +699,7 @@
         subject_token = credentials.retrieve_subject_token(request)
 
         assert subject_token == JSON_FILE_SUBJECT_TOKEN
-        self.assert_credential_request_kwargs(request.call_args_list[0].kwargs, None)
+        self.assert_credential_request_kwargs(request.call_args_list[0][1], None)
 
     def test_retrieve_subject_token_from_url_json_with_headers(self):
         credentials = self.make_credentials(
@@ -714,7 +714,7 @@
 
         assert subject_token == JSON_FILE_SUBJECT_TOKEN
         self.assert_credential_request_kwargs(
-            request.call_args_list[0].kwargs, {"foo": "bar"}
+            request.call_args_list[0][1], {"foo": "bar"}
         )
 
     def test_retrieve_subject_token_from_url_not_found(self):
diff --git a/tests/test_impersonated_credentials.py b/tests/test_impersonated_credentials.py
index 430c770..90de704 100644
--- a/tests/test_impersonated_credentials.py
+++ b/tests/test_impersonated_credentials.py
@@ -203,7 +203,7 @@
         assert credentials.valid
         assert not credentials.expired
         # Confirm override endpoint used.
-        request_kwargs = request.call_args.kwargs
+        request_kwargs = request.call_args[1]
         assert request_kwargs["url"] == self.IAM_ENDPOINT_OVERRIDE
 
     @pytest.mark.parametrize("time_skew", [100, -100])
@@ -378,7 +378,7 @@
         assert quota_project_creds.valid
         assert not quota_project_creds.expired
         # Confirm override endpoint used.
-        request_kwargs = request.call_args.kwargs
+        request_kwargs = request.call_args[1]
         assert request_kwargs["url"] == self.IAM_ENDPOINT_OVERRIDE
 
     def test_id_token_success(