diff --git a/lib/ansible/module_utils/gcp.py b/lib/ansible/module_utils/gcp.py
index 91c32d58baf..3e662d3bf14 100644
--- a/lib/ansible/module_utils/gcp.py
+++ b/lib/ansible/module_utils/gcp.py
@@ -240,11 +240,11 @@ def _validate_credentials_file(module, credentials_file, require_valid_json=True
                                      'Upgrade to libcloud>=0.17.0.')
             return True
     except IOError as e:
-        module.fail_json(msg='GCP Credentials File %s not found.', changed=False)
+        module.fail_json(msg='GCP Credentials File %s not found.' % credentials_file, changed=False)
         return False
     except ValueError as e:
         if require_valid_json:
-            module.fail_json(msg='GCP Credentials File %s invalid.  Must be valid JSON.', changed=False)
+            module.fail_json(msg='GCP Credentials File %s invalid.  Must be valid JSON.' % credentials_file, changed=False)
         else:
             display.deprecated(msg=("Non-JSON credentials file provided. This format is deprecated. "
                                     " Please generate a new JSON key from the Google Cloud console"),
diff --git a/lib/ansible/modules/cloud/google/gce.py b/lib/ansible/modules/cloud/google/gce.py
index b89be8dba2e..6c95b6eeb81 100644
--- a/lib/ansible/modules/cloud/google/gce.py
+++ b/lib/ansible/modules/cloud/google/gce.py
@@ -637,8 +637,8 @@ def main():
             zone = dict(default='us-central1-a'),
             service_account_email = dict(),
             service_account_permissions = dict(type='list'),
-            pem_file = dict(),
-            credentials_file = dict(),
+            pem_file = dict(type='path'),
+            credentials_file = dict(type='path'),
             project_id = dict(),
             ip_forward = dict(type='bool', default=False),
             external_ip=dict(default='ephemeral'),