diff --git a/lib/carto/torque-reference.js b/lib/carto/torque-reference.js
index 0b9f204..9422165 100644
--- a/lib/carto/torque-reference.js
+++ b/lib/carto/torque-reference.js
@@ -311,7 +311,8 @@ var _mapnik_reference_latest = {
                 "type": "float",
                 "doc": "The opacity of the polygon",
                 "default-value": 1,
-                "default-meaning": "opaque"
+                "default-meaning": "opaque",
+                "expression": true
             },
             "gamma": {
                 "css": "polygon-gamma",
@@ -585,7 +586,8 @@ var _mapnik_reference_latest = {
                 "doc": "An SVG file that this marker shows at each placement. If no file is given, the marker will show an ellipse.",
                 "default-value": "",
                 "default-meaning": "An ellipse or circle, if width equals height",
-                "type": "uri"
+                "type": "uri",
+                "expression": true
             },
             "opacity": {
                 "css": "marker-opacity",