diff --git a/pygeoapi/openapi.py b/pygeoapi/openapi.py
index 46ec1aa..e3c5db3 100644
--- a/pygeoapi/openapi.py
+++ b/pygeoapi/openapi.py
@@ -36,6 +36,10 @@ from pygeoapi.plugin import load_plugin
 
 LOGGER = logging.getLogger(__name__)
 
+SCHEMAS = {
+    'wps': 'https://raw.githubusercontent.com/opengeospatial/wps-rest-binding/master/core/openapi/schemas'  # noqa
+}
+
 
 def get_oas_30(cfg):
     """
@@ -334,7 +338,7 @@ def get_oas_30(cfg):
                     'content': {
                         'application/json': {
                             'schema': {
-                                '$ref': 'execute.yaml'
+                                '$ref': '{}/{}'.format(SCHEMAS['wps'], 'execute.yaml')  # noqa
                             }
                         }
                     }