diff --git a/os_api_ref/__init__.py b/os_api_ref/__init__.py
index f427fd8..ea83d34 100644
--- a/os_api_ref/__init__.py
+++ b/os_api_ref/__init__.py
@@ -223,9 +223,9 @@ class RestParametersDirective(Table):
             with open(fpath, 'r') as stream:
                 lookup = ordered_load(stream)
         except IOError:
-            self.env.warn(
-                self.env.docname,
-                "Parameters file %s not found" % fpath)
+            self.app.warn(
+                "Parameters file %s not found" % fpath,
+                (self.env.docname, None))
             return
         except yaml.YAMLError as exc:
             self.app.warn(exc)
@@ -234,9 +234,9 @@ class RestParametersDirective(Table):
         if lookup:
             self._check_yaml_sorting(fpath, lookup)
         else:
-            self.env.warn(
-                self.env.docname,
-                "Parameters file is empty %s" % fpath)
+            self.app.warn(
+                "Parameters file is empty %s" % fpath,
+                (self.env.docname, None))
             return
 
         YAML_CACHE[fpath] = lookup
@@ -306,29 +306,27 @@ class RestParametersDirective(Table):
         new_content = list()
         for paramlist in parsed:
             if not isinstance(paramlist, dict):
-                self.env.warn(
-                    "%s:%s" % (
-                        self.state_machine.node.source,
-                        self.state_machine.node.line),
+                self.app.warn(
                     ("Invalid parameter definition ``%s``. Expected "
                      "format: ``name: reference``. "
-                     " Skipping." % paramlist))
+                     " Skipping." % paramlist),
+                    (self.state_machine.node.source,
+                     self.state_machine.node.line))
                 continue
             for name, ref in paramlist.items():
                 if ref in lookup:
                     new_content.append((name, lookup[ref]))
                 else:
                     # TODO(sdague): this provides a kind of confusing
-                    # error message because env.warn isn't meant to be
+                    # error message because app.warn isn't meant to be
                     # used this way, however it does provide a way to
                     # track down where the parameters list is that is
                     # wrong. So it's good enough for now.
-                    self.env.warn(
-                        "%s:%s " % (
-                            self.state_machine.node.source,
-                            self.state_machine.node.line),
+                    self.app.warn(
                         ("No field definition for ``%s`` found in ``%s``. "
-                         " Skipping." % (ref, fpath)))
+                         " Skipping." % (ref, fpath)),
+                        (self.state_machine.node.source,
+                         self.state_machine.node.line))
 
                 # Check for path params in stanza
                 for i, param in enumerate(self.env.path_params):
@@ -342,13 +340,12 @@ class RestParametersDirective(Table):
             # Warn that path parameters are not set in rest_parameter
             # stanza and will not appear in the generated table.
             for param in self.env.path_params:
-                self.env.warn(
-                    "%s:%s " % (
-                        self.state_machine.node.source,
-                        self.state_machine.node.line),
+                self.app.warn(
                     ("No path parameter ``%s`` found in rest_parameter"
                      " stanza.\n"
-                     % param.rstrip('}').lstrip('{')))
+                     % param.rstrip('}').lstrip('{')),
+                    (self.state_machine.node.source,
+                     self.state_machine.node.line))
 
         # self.app.info("New content %s" % new_content)
         self.yaml = new_content
diff --git a/os_api_ref/http_codes.py b/os_api_ref/http_codes.py
index 317be89..fdabdbf 100644
--- a/os_api_ref/http_codes.py
+++ b/os_api_ref/http_codes.py
@@ -49,9 +49,9 @@ class HTTPResponseCodeDirective(Table):
             with open(fpath, 'r') as stream:
                 lookup = yaml.safe_load(stream)
         except IOError:
-            self.env.warn(
-                self.env.docname,
-                "Parameters file %s not found" % fpath)
+            self.app.warn(
+                "Parameters file %s not found" % fpath,
+                (self.env.docname, None))
             return
         except yaml.YAMLError as exc:
             self.app.warn(exc)
diff --git a/os_api_ref/tests/test_warnings.py b/os_api_ref/tests/test_warnings.py
index 6e98471..7c3a5f2 100644
--- a/os_api_ref/tests/test_warnings.py
+++ b/os_api_ref/tests/test_warnings.py
@@ -62,7 +62,7 @@ class TestWarnings(base.TestCase):
              + "OrderedDict([('description',"
              + " 'name_1 is missing type field.\\n'), ('in', 'body'),"
              + " ('required', True)]). "
-             + "'NoneType' object has no attribute 'split'\n"),
+             + "'NoneType' object has no attribute 'split'"),
             self.warning)
 
     def test_invalid_parameter_definition(self):
@@ -81,15 +81,15 @@ class TestWarnings(base.TestCase):
     def test_no_parameters_set(self):
         """Error when parameters are not set in rest_parameters stanza."""
         self.assertIn(
-            ("ERROR: No parameters defined\n\n.."
-             + " rest_parameters:: parameters.yaml\n"),
+            ("No parameters defined\n\n.."
+             + " rest_parameters:: parameters.yaml"),
             self.warning)
 
     def test_parameter_file_not_exist(self):
         """Error when parameter file does not exist"""
         self.assertIn(
-            ("ERROR: No parameters defined\n\n.."
-             + " rest_parameters:: no_parameters.yaml\n"),
+            ("No parameters defined\n\n.."
+             + " rest_parameters:: no_parameters.yaml"),
             self.warning)
 
     def test_missing_path_parameter_in_stanza(self):