diff --git a/tempest/common/preprov_creds.py b/tempest/common/preprov_creds.py
index e154842..eac7f4e 100644
--- a/tempest/common/preprov_creds.py
+++ b/tempest/common/preprov_creds.py
@@ -249,7 +249,7 @@
             'utf-8'), None)
         # The force kwarg is used to allocate an additional set of creds with
         # the same role list. The index used for the previously allocation
-        # in the preprov_creds dict will be moved.
+        # in the _creds dict will be moved.
         if exist_creds and not force_new:
             return exist_creds
         elif exist_creds and force_new:
diff --git a/tempest/services/compute/json/fixed_ips_client.py b/tempest/services/compute/json/fixed_ips_client.py
index d826655..7b374aa 100644
--- a/tempest/services/compute/json/fixed_ips_client.py
+++ b/tempest/services/compute/json/fixed_ips_client.py
@@ -33,4 +33,4 @@
         url = "os-fixed-ips/%s/action" % fixed_ip
         resp, body = self.post(url, json.dumps(kwargs))
         self.validate_response(schema.reserve_unreserve_fixed_ip, resp, body)
-        return service_client.ResponseBody(resp)
+        return service_client.ResponseBody(resp, body)
diff --git a/tempest/tests/services/compute/test_fixedIPs_client.py b/tempest/tests/services/compute/test_fixedIPs_client.py
index 5acb422..b537baa 100644
--- a/tempest/tests/services/compute/test_fixedIPs_client.py
+++ b/tempest/tests/services/compute/test_fixedIPs_client.py
@@ -44,3 +44,16 @@
 
     def test_show_fixed_ip_with_bytes_body(self):
         self._test_show_fixed_ip(True)
+
+    def _test_reserve_fixed_ip(self, bytes_body=False):
+        self.check_service_client_function(
+            self.fixedIPsClient.reserve_fixed_ip,
+            'tempest.common.service_client.ServiceClient.post',
+            {}, bytes_body,
+            status=202, fixed_ip='Identifier')
+
+    def test_reserve_fixed_ip_with_str_body(self):
+        self._test_reserve_fixed_ip()
+
+    def test_reserve_fixed_ip_with_bytes_body(self):
+        self._test_reserve_fixed_ip(True)