diff --git a/plugins/module_utils/gcp_utils.py b/plugins/module_utils/gcp_utils.py
index d08298b..ec8c73e 100644
--- a/plugins/module_utils/gcp_utils.py
+++ b/plugins/module_utils/gcp_utils.py
@@ -18,7 +18,7 @@ except ImportError:
 
 from ansible.module_utils.basic import AnsibleModule, env_fallback
 from ansible.module_utils.six import string_types
-from ansible.module_utils._text import to_text
+from ansible.module_utils._text import to_text, to_native
 import ast
 import os
 import json
@@ -86,7 +86,7 @@ class GcpSession(object):
 
     def post(self, url, body=None, headers=None, **kwargs):
         if headers:
-            headers = self.merge_dictionaries(headers, self._headers())
+            headers = self._merge_dictionaries(headers, self._headers())
         else:
             headers = self._headers()
 
@@ -97,7 +97,7 @@ class GcpSession(object):
 
     def post_contents(self, url, file_contents=None, headers=None, **kwargs):
         if headers:
-            headers = self.merge_dictionaries(headers, self._headers())
+            headers = self._merge_dictionaries(headers, self._headers())
         else:
             headers = self._headers()
 
@@ -156,7 +156,12 @@ class GcpSession(object):
             path = os.path.realpath(os.path.expanduser(self.module.params['service_account_file']))
             return service_account.Credentials.from_service_account_file(path).with_scopes(self.module.params['scopes'])
         elif cred_type == 'serviceaccount' and self.module.params.get('service_account_contents'):
-            cred = json.loads(self.module.params.get('service_account_contents'))
+            try:
+                cred = json.loads(self.module.params.get('service_account_contents'))
+            except json.decoder.JSONDecodeError as e:
+                self.module.fail_json(
+                    msg="Unable to decode service_account_contents as JSON"
+                )
             return service_account.Credentials.from_service_account_info(cred).with_scopes(self.module.params['scopes'])
         elif cred_type == 'machineaccount':
             return google.auth.compute_engine.Credentials(