diff --git a/src/generators/shared/processCss.js b/src/generators/shared/processCss.js
index 4f57e4db70..51abf2a292 100644
--- a/src/generators/shared/processCss.js
+++ b/src/generators/shared/processCss.js
@@ -1,4 +1,3 @@
-import parse from 'css-tree/lib/parser/index.js';
 import walk from 'css-tree/lib/utils/walk.js';
 
 const commentsPattern = /\/\*[\s\S]*?\*\//g;
@@ -7,16 +6,12 @@ export default function processCss ( parsed, code ) {
 	const css = parsed.css.content.styles;
 	const offset = parsed.css.content.start;
 
-	const ast = parse( css, {
-		positions: true
-	});
-
 	const attr = `[svelte-${parsed.hash}]`;
 
-	walk.rules( ast, rule => {
+	walk.rules( parsed.css.ast, rule => {
 		rule.selector.children.each( selector => {
-			const start = selector.loc.start.offset;
-			const end = selector.loc.end.offset;
+			const start = selector.start - offset;
+			const end = selector.end - offset;
 
 			const selectorString = css.slice( start, end );
 
@@ -25,7 +20,7 @@ export default function processCss ( parsed, code ) {
 			let transformed;
 
 			if ( firstToken.data.type === 'TypeSelector' ) {
-				const insert = firstToken.data.loc.end.offset;
+				const insert = firstToken.data.end - offset;
 				const head = css.slice( start, insert );
 				const tail = css.slice( insert, end );
 
@@ -41,7 +36,7 @@ export default function processCss ( parsed, code ) {
 	// remove comments. TODO would be nice if this was exposed in css-tree
 	let match;
 	while ( match = commentsPattern.exec( css ) ) {
-		const start = match.index + offset;
+		const start = match.index;
 		const end = start + match[0].length;
 
 		code.remove( start, end );
diff --git a/src/parse/read/style.js b/src/parse/read/style.js
index 5da3cc2d4c..fb2fb2e780 100644
--- a/src/parse/read/style.js
+++ b/src/parse/read/style.js
@@ -1,8 +1,25 @@
+import parse from 'css-tree/lib/parser/index.js';
+import walk from 'css-tree/lib/utils/walk.js';
+
 export default function readStyle ( parser, start, attributes ) {
 	const contentStart = parser.index;
 	const styles = parser.readUntil( /<\/style>/ );
 	const contentEnd = parser.index;
 
+	const ast = parse( styles, {
+		positions: true,
+		offset: contentStart
+	});
+
+	// tidy up AST
+	walk.all( ast, node => {
+		if ( node.loc ) {
+			node.start = node.loc.start.offset;
+			node.end = node.loc.end.offset;
+			delete node.loc;
+		}
+	});
+
 	parser.eat( '</style>', true );
 	const end = parser.index;
 
@@ -10,6 +27,7 @@ export default function readStyle ( parser, start, attributes ) {
 		start,
 		end,
 		attributes,
+		ast,
 		content: {
 			start: contentStart,
 			end: contentEnd,
diff --git a/test/parse.js b/test/parse.js
index 166a17609b..fa8cf85d8d 100644
--- a/test/parse.js
+++ b/test/parse.js
@@ -16,7 +16,7 @@ describe( 'parse', () => {
 			const input = fs.readFileSync( `test/parser/${dir}/input.html`, 'utf-8' ).replace( /\s+$/, '' );
 
 			try {
-				const actual = svelte.parse( input );
+				const actual = JSON.parse( JSON.stringify( svelte.parse( input ) ) );
 				const expected = require( `./parser/${dir}/output.json` );
 
 				assert.deepEqual( actual.html, expected.html );
diff --git a/test/parser/css/output.json b/test/parser/css/output.json
index 1e78e04cf5..5efa084f7d 100644
--- a/test/parser/css/output.json
+++ b/test/parser/css/output.json
@@ -29,6 +29,65 @@
 			"start": 23,
 			"end": 48,
 			"styles": "\n\tdiv {\n\t\tcolor: red;\n\t}\n"
+		},
+		"ast": {
+			"type": "StyleSheet",
+			"start": 23,
+			"end": 48,
+			"children": [
+				{
+					"type": "Rule",
+					"start": 25,
+					"end": 47,
+					"selector": {
+						"type": "SelectorList",
+						"start": 25,
+						"end": 28,
+						"children": [
+							{
+								"type": "Selector",
+								"start": 25,
+								"end": 28,
+								"children": [
+									{
+										"type": "TypeSelector",
+										"start": 25,
+										"end": 28,
+										"name": "div"
+									}
+								]
+							}
+						]
+					},
+					"block": {
+						"type": "Block",
+						"start": 29,
+						"end": 47,
+						"children": [
+							{
+								"type": "Declaration",
+								"start": 33,
+								"end": 43,
+								"important": false,
+								"property": "color",
+								"value": {
+									"type": "Value",
+									"start": 39,
+									"end": 43,
+									"children": [
+										{
+											"type": "Identifier",
+											"start": 40,
+											"end": 43,
+											"name": "red"
+										}
+									]
+								}
+							}
+						]
+					}
+				}
+			]
 		}
 	},
 	"js": null