diff --git a/src/core/create_compilers/extract_css.ts b/src/core/create_compilers/extract_css.ts
index 663abd9a5..e885154c9 100644
--- a/src/core/create_compilers/extract_css.ts
+++ b/src/core/create_compilers/extract_css.ts
@@ -3,7 +3,7 @@ import * as path from 'path';
 import hash from 'string-hash';
 import * as codec from 'sourcemap-codec';
 import { PageComponent, Dirs } from '../../interfaces';
-import { CompileResult } from './interfaces';
+import { CompileResult, Chunk } from './interfaces';
 import { posixify } from '../../utils'
 
 const inline_sourcemap_header = 'data:application/json;charset=utf-8;base64,';
@@ -46,6 +46,65 @@ type SourceMap = {
 	mappings: string;
 };
 
+function get_css_from_modules(modules: string[], css_map: Map<string, string>, dirs: Dirs) {
+	const parts: string[] = [];
+	const mappings: number[][][] = [];
+
+	const combined_map: SourceMap = {
+		version: 3,
+		file: null,
+		sources: [],
+		sourcesContent: [],
+		names: [],
+		mappings: null
+	};
+
+	modules.forEach(module => {
+		if (!/\.css$/.test(module)) return;
+
+		const css = css_map.get(module);
+
+		const { code, map } = extract_sourcemap(css, module);
+
+		parts.push(code);
+
+		if (map) {
+			const lines = codec.decode(map.mappings);
+
+			if (combined_map.sources.length > 0 || combined_map.names.length > 0) {
+				lines.forEach(line => {
+					line.forEach(segment => {
+						// adjust source index
+						segment[1] += combined_map.sources.length;
+
+						// adjust name index
+						if (segment[4]) segment[4] += combined_map.names.length;
+					});
+				});
+			}
+
+			combined_map.sources.push(...map.sources);
+			combined_map.sourcesContent.push(...map.sourcesContent);
+			combined_map.names.push(...map.names);
+
+			mappings.push(...lines);
+		}
+	});
+
+	if (parts.length > 0) {
+		combined_map.mappings = codec.encode(mappings);
+
+		combined_map.sources = combined_map.sources.map(source => path.relative(`${dirs.dest}/client`, source));
+
+		return {
+			code: parts.join('\n'),
+			map: combined_map
+		};
+	}
+
+	return null;
+}
+
 export default function extract_css(client_result: CompileResult, components: PageComponent[], dirs: Dirs) {
 	const result: {
 		main: string | null;
@@ -57,151 +116,94 @@ export default function extract_css(client_result: CompileResult, components: Pa
 
 	if (!client_result.css_files) return; // Rollup-only for now
 
-	const unaccounted_for = new Set();
+	let asset_dir = `${dirs.dest}/client`;
+	if (process.env.SAPPER_LEGACY_BUILD) asset_dir += '/legacy';
 
-	const css_map = new Map();
-	client_result.css_files.forEach(css => {
-		unaccounted_for.add(css.id);
-		css_map.set(css.id, css.code);
-	});
+	const unclaimed = new Set(client_result.css_files.map(x => x.id));
 
-	const chunk_map = new Map();
+	const lookup = new Map();
 	client_result.chunks.forEach(chunk => {
-		chunk_map.set(chunk.file, chunk);
+		lookup.set(chunk.file, chunk);
 	});
 
-	const chunks_with_css = new Set();
-
-	// figure out which chunks belong to which components...
-	const component_owners = new Map();
-	client_result.chunks.forEach(chunk => {
-		chunk.modules.forEach(module => {
-			const component = posixify(path.relative(dirs.routes, module));
-			component_owners.set(component, chunk);
-		});
+	const css_map = new Map();
+	client_result.css_files.forEach(css_module => {
+		css_map.set(css_module.id, css_module.code);
 	});
 
-	const chunks_depended_upon_by_component = new Map();
-
-	// ...so we can figure out which chunks don't belong
-	components.forEach(component => {
-		const chunk = component_owners.get(component.file);
-		if (!chunk) {
-			// this should never happen!
-			throw new Error(`Could not find chunk that owns ${component.file}`);
-		}
-
-		const chunks = new Set([chunk]);
-		chunks.forEach(chunk => {
-			chunk.imports.forEach((file: string) => {
-				const chunk = chunk_map.get(file);
-				if (chunk) chunks.add(chunk);
-			});
-		});
-
-		chunks.forEach(chunk => {
-			chunk.modules.forEach((module: string) => {
-				unaccounted_for.delete(module);
-			});
-		});
-
-		chunks_depended_upon_by_component.set(
-			component,
-			chunks
-		);
-	});
+	const chunks_with_css = new Set();
 
-	function get_css_from_modules(modules: string[]) {
-		const parts: string[] = [];
-		const mappings: number[][][] = [];
-
-		const combined_map: SourceMap = {
-			version: 3,
-			file: null,
-			sources: [],
-			sourcesContent: [],
-			names: [],
-			mappings: null
-		};
+	// concatenate and emit CSS
+	client_result.chunks.forEach(chunk => {
+		const css_modules = chunk.modules.filter(m => css_map.has(m));
+		if (!css_modules.length) return;
 
-		modules.forEach(module => {
-			if (!/\.css$/.test(module)) return;
+		const css = get_css_from_modules(css_modules, css_map, dirs);
 
-			const css = css_map.get(module);
+		const { code, map } = css;
 
-			const { code, map } = extract_sourcemap(css, module);
+		const output_file_name = chunk.file.replace(/\.js$/, '.css');
 
-			parts.push(code);
+		map.file = output_file_name;
+		map.sources = map.sources.map(source => path.relative(`${asset_dir}`, source));
 
-			if (map) {
-				const lines = codec.decode(map.mappings);
+		fs.writeFileSync(`${asset_dir}/${output_file_name}`, `${code}\n/* sourceMappingURL=./${output_file_name}.map */`);
+		fs.writeFileSync(`${asset_dir}/${output_file_name}.map`, JSON.stringify(map, null, '  '));
 
-				if (combined_map.sources.length > 0 || combined_map.names.length > 0) {
-					lines.forEach(line => {
-						line.forEach(segment => {
-							// adjust source index
-							segment[1] += combined_map.sources.length;
+		chunks_with_css.add(chunk);
+	});
 
-							// adjust name index
-							if (segment[4]) segment[4] += combined_map.names.length;
-						});
-					});
-				}
+	const entry = path.resolve(dirs.src, 'client.js');
+	const entry_chunk = client_result.chunks.find(chunk => chunk.modules.indexOf(entry) !== -1);
 
-				combined_map.sources.push(...map.sources);
-				combined_map.sourcesContent.push(...map.sourcesContent);
-				combined_map.names.push(...map.names);
+	const entry_chunk_dependencies: Set<Chunk> = new Set([entry_chunk]);
+	const entry_css_modules: string[] = [];
 
-				mappings.push(...lines);
-			}
+	// recursively find the chunks this component depends on
+	entry_chunk_dependencies.forEach(chunk => {
+		chunk.imports.forEach(file => {
+			entry_chunk_dependencies.add(lookup.get(file));
 		});
 
-		if (parts.length > 0) {
-			combined_map.mappings = codec.encode(mappings);
-
-			combined_map.sources = combined_map.sources.map(source => path.relative(`${dirs.dest}/client`, source));
-
-			return {
-				code: parts.join('\n'),
-				map: combined_map
-			};
+		if (chunks_with_css.has(chunk)) {
+			chunk.modules.forEach(file => {
+				unclaimed.delete(file);
+				if (css_map.has(file)) {
+					entry_css_modules.push(file);
+				}
+			});
 		}
+	});
 
-		return null;
-	}
-
-	let asset_dir = `${dirs.dest}/client`;
-	if (process.env.SAPPER_LEGACY_BUILD) asset_dir += '/legacy';
-
-	const replacements = new Map();
-
-	chunks_depended_upon_by_component.forEach((chunks, component) => {
-		const chunks_with_css = Array.from(chunks).filter(chunk => {
-			const css = get_css_from_modules(chunk.modules);
+	// figure out which (css-having) chunks each component depends on
+	components.forEach(component => {
+		const resolved = path.resolve(dirs.routes, component.file);
+		const chunk: Chunk = client_result.chunks.find(chunk => chunk.modules.indexOf(resolved) !== -1);
 
-			if (css) {
-				const { code, map } = css;
+		if (!chunk) {
+			// this should never happen!
+			throw new Error(`Could not find chunk that owns ${component.file}`);
+		}
 
-				const output_file_name = chunk.file.replace(/\.js$/, '.css');
+		const chunk_dependencies: Set<Chunk> = new Set([chunk]);
+		const css_dependencies: string[] = [];
 
-				map.file = output_file_name;
-				map.sources = map.sources.map(source => path.relative(`${asset_dir}`, source));
+		// recursively find the chunks this component depends on
+		chunk_dependencies.forEach(chunk => {
+			chunk.imports.forEach(file => {
+				chunk_dependencies.add(lookup.get(file));
+			});
 
-				fs.writeFileSync(`${asset_dir}/${output_file_name}`, `${code}\n/* sourceMappingURL=./${output_file_name}.map */`);
-				fs.writeFileSync(`${asset_dir}/${output_file_name}.map`, JSON.stringify(map, null, '  '));
+			if (chunks_with_css.has(chunk)) {
+				css_dependencies.push(chunk.file.replace(/\.js$/, '.css'));
 
-				return true;
+				chunk.modules.forEach(file => {
+					unclaimed.delete(file);
+				});
 			}
 		});
 
-		const files = chunks_with_css.map(chunk => chunk.file.replace(/\.js$/, '.css'));
-
-		replacements.set(
-			component.file,
-			files
-		);
-
-		result.chunks[component.file] = files;
+		result.chunks[component.file] = css_dependencies;
 	});
 
 	fs.readdirSync(asset_dir).forEach(file => {
@@ -210,13 +212,17 @@ export default function extract_css(client_result: CompileResult, components: Pa
 		const source = fs.readFileSync(`${asset_dir}/${file}`, 'utf-8');
 
 		const replaced = source.replace(/["']__SAPPER_CSS_PLACEHOLDER:(.+?)__["']/g, (m, route) => {
-			return JSON.stringify(replacements.get(route));
+			return JSON.stringify(result.chunks[route]);
 		});
 
 		fs.writeFileSync(`${asset_dir}/${file}`, replaced);
 	});
 
-	const leftover = get_css_from_modules(Array.from(unaccounted_for));
+	unclaimed.forEach(file => {
+		entry_css_modules.push(css_map.get(file));
+	});
+
+	const leftover = get_css_from_modules(entry_css_modules, css_map, dirs);
 	if (leftover) {
 		const { code, map } = leftover;