diff --git a/CHANGELOG.md b/CHANGELOG.md
index 72a8164..3854c57 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 ## Changelog
 
+### 0.7.0
+
+* Support an `opacity` property on any style that is a style-level property
+
 ### 0.6.0
 
 * Bump `mapnik-reference` dependency to 1.0.0 to allow for using `buffer-size` in the
diff --git a/lib/carto/tree/style.js b/lib/carto/tree/style.js
index 4c99e5e..8211dda 100644
--- a/lib/carto/tree/style.js
+++ b/lib/carto/tree/style.js
@@ -9,7 +9,7 @@ tree.Style = function Style(name, attachment, definitions) {
 
 tree.Style.prototype.toXML = function(env) {
     var existing = {};
-    // TODO :add filters and comp op
+
     var image_filters = _.flatten(this.definitions.map(function(definition) {
         return definition.rules.filter(function(rule) {
             return (rule.name === 'image-filters');
@@ -22,24 +22,33 @@ tree.Style.prototype.toXML = function(env) {
         });
     }));
 
+    var opacity = _.flatten(this.definitions.map(function(definition) {
+        return definition.rules.filter(function(rule) {
+            return (rule.name === 'opacity');
+        });
+    }));
+
     var rules = this.definitions.map(function(definition) {
         return definition.toXML(env, existing);
     });
 
-    var image_filters_xml = '',
-        comp_op_xml = '';
+    var attrs_xml = '';
 
     if (image_filters.length) {
-        image_filters_xml = 'image-filters="' + image_filters.map(function(f) {
+        attrs_xml += ' image-filters="' + image_filters.map(function(f) {
             return f.toXML(env, true);
-        }).join(',') + '"';
+        }).join(',') + '" ';
     }
     
     if (comp_op.length) {
-        comp_op_xml = 'comp-op="' + comp_op[0].value.eval(env).toString() + '"';
+        attrs_xml += ' comp-op="' + comp_op[0].value.eval(env).toString() + '" ';
     }
 
-    return '<Style name="' + this.name + '" filter-mode="first" ' + image_filters_xml + ' ' + comp_op_xml + '>\n' + rules.join('') + '</Style>';
+    if (opacity.length) {
+        attrs_xml += ' opacity="' + opacity[0].value.eval(env).toString() + '" ';
+    }
+
+    return '<Style name="' + this.name + '" filter-mode="first" ' + attrs_xml + '>\n' + rules.join('') + '</Style>';
 };
 
 })(require('../tree'));
diff --git a/package.json b/package.json
index 067f52b..f07837e 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "carto",
-  "version": "0.6.0",
+  "version": "0.7.0",
   "description": "Mapnik Stylesheet Compiler",
   "url": "https://github.com/mapbox/carto",
   "repositories": [{
@@ -36,7 +36,7 @@
   },
   "dependencies": {
     "underscore": "~1.3.3",
-    "mapnik-reference": "~2.0.0",
+    "mapnik-reference": "~2.1.0",
     "xml2js": "~0.1.13"
   },
   "devDependencies": {
diff --git a/test/rendering/style_level_opacity.mml b/test/rendering/style_level_opacity.mml
new file mode 100644
index 0000000..160ebc8
--- /dev/null
+++ b/test/rendering/style_level_opacity.mml
@@ -0,0 +1,14 @@
+{
+    "srs": "+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0.0 +k=1.0 +units=m +nadgrids=@null +wktext +no_defs +over",
+    "Stylesheet": [
+        "style_level_opacity.mss"
+    ],
+    "Layer": [{
+        "name": "world",
+        "srs": "+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0.0 +k=1.0 +units=m +nadgrids=@null +wktext +no_defs +over",
+        "Datasource": {
+            "file": "http://tilemill-data.s3.amazonaws.com/test_data/shape_demo.zip",
+            "type": "shape"
+        }
+    }]
+}
diff --git a/test/rendering/style_level_opacity.mss b/test/rendering/style_level_opacity.mss
new file mode 100644
index 0000000..ea06e8f
--- /dev/null
+++ b/test/rendering/style_level_opacity.mss
@@ -0,0 +1,6 @@
+#world {
+  opacity:0.2;
+  text-name: "[NAME]";
+  text-size: 11;
+  text-face-name: "Georgia Regular", "Arial Italic";
+}
diff --git a/test/rendering/style_level_opacity.result b/test/rendering/style_level_opacity.result
new file mode 100644
index 0000000..f6132f9
--- /dev/null
+++ b/test/rendering/style_level_opacity.result
@@ -0,0 +1,23 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!DOCTYPE Map[]>
+<Map srs="+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0.0 +k=1.0 +units=m +nadgrids=@null +wktext +no_defs +over" maximum-extent="-20037508.34,-20037508.34,20037508.34,20037508.34">
+
+<FontSet name="fontset-0">
+  <Font face-name="Georgia Regular"/>
+  <Font face-name="Arial Italic"/>
+</FontSet>
+<Style name="world" filter-mode="first"  opacity="0.2" >
+  <Rule>
+    <TextSymbolizer size="11" fontset-name="fontset-0" ><![CDATA[[NAME]]]></TextSymbolizer>
+  </Rule>
+</Style>
+<Layer name="world"
+  srs="+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0.0 +k=1.0 +units=m +nadgrids=@null +wktext +no_defs +over">
+    <StyleName>world</StyleName>
+    <Datasource>
+       <Parameter name="file"><![CDATA[[absolute path]]]></Parameter>
+       <Parameter name="type"><![CDATA[shape]]></Parameter>
+    </Datasource>
+  </Layer>
+
+</Map>