diff --git a/README.md b/README.md
index e54698b4..cc126f1a 100755
--- a/README.md
+++ b/README.md
@@ -126,23 +126,6 @@ Default: `[]`
 
 A string or an array of paths in where to look for files.
 
-#### `transform`
-
-Type: `Function`  
-Default: `null`
-
-A function to transform the content of imported files. Take one argument (file
-  content) and should return the modified content or a resolved promise with it.
-`undefined` result will be skipped.
-
-```js
-transform: function(css) {
-  return postcss([somePlugin]).process(css).then(function(result) {
-    return result.css;
-  });
-}
-```
-
 #### `plugins`
 
 Type: `Array`  
@@ -163,10 +146,12 @@ files).
 Type: `Function`  
 Default: `null`
 
-You can overwrite the default path resolving way by setting this option.
-This function gets `(id, basedir, importOptions)` arguments and returns full
-path, array of paths or promise resolving paths.
-You can use [resolve](https://github.com/substack/node-resolve) for that.
+You can provide a custom path resolver with this option. This function gets
+`(id, basedir, importOptions)` arguments and should return a path, an array of
+paths or a promise resolving to the path(s). If you do not return an absolute
+path, your path will be resolved to an absolute path using the default
+resolver.
+You can use [resolve](https://github.com/substack/node-resolve) for this.
 
 #### `load`
 
@@ -230,6 +215,13 @@ postcss()
   })
 ```
 
+### jspm Usage
+
+postcss-import can `@import` [jspm](http://jspm.io) dependencies if
+[`pkg-resolve`](https://www.npmjs.com/package/pkg-resolve) is installed by the
+user. Run `npm install pkg-resolve` to install it. postcss-import should then be
+able to import from jspm dependencies without further configuration.
+
 ## `dependency` Message Support
 
 `postcss-import` adds a message to `result.messages` for each `@import`. Messages are in the following format:
diff --git a/index.js b/index.js
index e8a7deb8..4d3e945a 100755
--- a/index.js
+++ b/index.js
@@ -4,6 +4,7 @@ var postcss = require("postcss")
 var joinMedia = require("./lib/join-media")
 var resolveId = require("./lib/resolve-id")
 var loadContent = require("./lib/load-content")
+var processContent = require("./lib/process-content")
 var parseStatements = require("./lib/parse-statements")
 var promiseEach = require("promise-each")
 
@@ -62,6 +63,14 @@ function AtImport(options) {
         typeof options.addDependencyTo === "object" &&
         typeof options.addDependencyTo.addDependency === "function"
       ) {
+        console.warn([
+          "addDependencyTo is deprecated in favor of",
+          "result.messages.dependency; postcss-loader >= v1.0.0 will",
+          "automatically add your imported files to webpack's file watcher.",
+          "For more information, see",
+          "https://github.com/postcss/postcss-import\
+          #dependency-message-support",
+        ].join("\n"))
         Object.keys(state.importedFiles)
         .forEach(options.addDependencyTo.addDependency)
       }
@@ -227,11 +236,18 @@ function resolveImportId(
     : options.root
 
   return Promise.resolve(options.resolve(stmt.uri, base, options))
-  .then(function(resolved) {
-    if (!Array.isArray(resolved)) {
-      resolved = [ resolved ]
+  .then(function(paths) {
+    if (!Array.isArray(paths)) {
+      paths = [ paths ]
     }
 
+    return Promise.all(paths.map(function(file) {
+      // Ensure that each path is absolute:
+      if (!path.isAbsolute(file)) return resolveId(file, base, options)
+      return file
+    }))
+  })
+  .then(function(resolved) {
     // Add dependency messages:
     resolved.forEach(function(file) {
       result.messages.push({
@@ -261,6 +277,7 @@ function resolveImportId(
     }, [])
   })
   .catch(function(err) {
+    if (err.message.indexOf("Failed to find") !== -1) throw err
     result.warn(err.message, { node: atRule })
   })
 }
@@ -291,15 +308,6 @@ function loadImportContent(
   }
 
   return Promise.resolve(options.load(filename, options))
-  .then(function(content) {
-    if (typeof options.transform !== "function") {
-      return content
-    }
-    return Promise.resolve(options.transform(content, filename, options))
-    .then(function(transformed) {
-      return typeof transformed === "string" ? transformed : content
-    })
-  })
   .then(function(content) {
     if (content.trim() === "") {
       result.warn(filename + " is empty", { node: atRule })
@@ -314,11 +322,12 @@ function loadImportContent(
       return
     }
 
-    return postcss(options.plugins).process(content, {
-      from: filename,
-      syntax: result.opts.syntax,
-      parser: result.opts.parser,
-    })
+    return processContent(
+      result,
+      content,
+      filename,
+      options
+    )
     .then(function(importedResult) {
       var styles = importedResult.root
       result.messages = result.messages.concat(importedResult.messages)
diff --git a/lib/process-content.js b/lib/process-content.js
new file mode 100644
index 00000000..5a63a20b
--- /dev/null
+++ b/lib/process-content.js
@@ -0,0 +1,61 @@
+var path = require("path")
+var postcss = require("postcss")
+var sugarss
+
+module.exports = function processContent(
+  result,
+  content,
+  filename,
+  options
+) {
+  var plugins = options.plugins
+  var ext = path.extname(filename)
+
+  var parserList = []
+
+  // SugarSS support:
+  if (ext === ".sss") {
+    if (!sugarss) {
+      try {
+        sugarss = require("sugarss")
+      }
+      catch (e) {
+        // Ignore
+      }
+    }
+    if (sugarss) return runPostcss(content, filename, plugins, [ sugarss ])
+  }
+
+  // Syntax support:
+  if (result.opts.syntax && result.opts.syntax.parse) {
+    parserList.push(result.opts.syntax.parse)
+  }
+
+  // Parser support:
+  if (result.opts.parser) parserList.push(result.opts.parser)
+  // Try the default as a last resort:
+  parserList.push(null)
+
+  return runPostcss(content, filename, plugins, parserList)
+}
+
+function runPostcss(
+  content,
+  filename,
+  plugins,
+  parsers,
+  index
+) {
+  if (!index) index = 0
+  return postcss(plugins).process(content, {
+    from: filename,
+    parser: parsers[index],
+  })
+  .catch(function(err) {
+    // If there's an error, try the next parser
+    index++
+    // If there are no parsers left, throw it
+    if (index === parsers.length) throw err
+    return runPostcss(content, filename, plugins, parsers, index)
+  })
+}
diff --git a/package.json b/package.json
index 71a3963b..fe12ffa6 100644
--- a/package.json
+++ b/package.json
@@ -30,10 +30,8 @@
     "eslint": "^1.10.3",
     "eslint-config-i-am-meticulous": "^2.0.0",
     "npmpub": "^3.0.1",
-    "postcss-scss": "^0.1.3"
-  },
-  "optionalDependencies": {
-    "pkg-resolve": "^0.1.7"
+    "postcss-scss": "^0.1.3",
+    "sugarss": "^0.2.0"
   },
   "jspm": {
     "name": "postcss-import",
diff --git a/test/custom-resolve.js b/test/custom-resolve.js
index 974bde58..b4453f67 100644
--- a/test/custom-resolve.js
+++ b/test/custom-resolve.js
@@ -1,5 +1,7 @@
 import test from "ava"
 import compareFixtures from "./helpers/compare-fixtures"
+import postcss from "postcss"
+import atImport from ".."
 import path from "path"
 
 test.serial("should accept file", t => {
@@ -43,3 +45,23 @@ test.serial("should accept promised array of files", t => {
     },
   })
 })
+
+test(
+  "should apply default resolver when custom doesn't return an absolute path",
+  function(t) {
+    return postcss()
+    .use(atImport({
+      resolve: path => {
+        return path.replace("foo", "imports/bar")
+      },
+      load: p => {
+        t.is(p, path.resolve("fixtures/imports", "bar.css"))
+        return "/* comment */"
+      },
+    }))
+    .process(`@import "foo.css";`, { from: "fixtures/custom-resolve-file" })
+    .then(result => {
+      t.is(result.css, "/* comment */")
+    })
+  }
+)
diff --git a/test/custom-syntax-parser.js b/test/custom-syntax-parser.js
new file mode 100644
index 00000000..c14589e6
--- /dev/null
+++ b/test/custom-syntax-parser.js
@@ -0,0 +1,43 @@
+import test from "ava"
+import scss from "postcss-scss"
+import sugarss from "sugarss"
+import compareFixtures from "./helpers/compare-fixtures"
+import compareFixturesExt from "./helpers/compare-fixtures-ext"
+
+test("should process custom syntax", t => {
+  return compareFixtures(t, "scss-syntax", null, {
+    syntax: scss,
+  })
+})
+
+test("should process custom syntax by parser", t => {
+  return compareFixtures(t, "scss-parser", null, {
+    parser: scss,
+  })
+})
+
+test(".css importing .sss should work", t => {
+  return compareFixtures(t, "import-sss")
+})
+
+test(".sss importing .sss should work", t => {
+  return compareFixturesExt(t, "sugar", ".sss", null, {
+    parser: sugarss,
+  })
+})
+
+test(".sss importing .css should work", t => {
+  return compareFixturesExt(t, "sugar-import-css", ".sss", null, {
+    parser: sugarss,
+  })
+})
+
+test(".css importing .sss importing .css should work", t => {
+  return compareFixtures(t, "import-sss-css")
+})
+
+test(".sss importing .css importing .sss should work", t => {
+  return compareFixturesExt(t, "import-css-sss", ".sss", null, {
+    parser: sugarss,
+  })
+})
diff --git a/test/fixtures/import-css-sss.expected.css b/test/fixtures/import-css-sss.expected.css
new file mode 100644
index 00000000..13de4796
--- /dev/null
+++ b/test/fixtures/import-css-sss.expected.css
@@ -0,0 +1,9 @@
+.sugarbar{
+  color: blue
+}
+
+import.sugarbar{}
+
+.sugar{
+  color: white
+}
diff --git a/test/fixtures/import-css-sss.sss b/test/fixtures/import-css-sss.sss
new file mode 100644
index 00000000..1af8c35a
--- /dev/null
+++ b/test/fixtures/import-css-sss.sss
@@ -0,0 +1,4 @@
+@import "import-sugarbar.css"
+
+.sugar
+  color: white
diff --git a/test/fixtures/import-sss-css.css b/test/fixtures/import-sss-css.css
new file mode 100644
index 00000000..c9b32274
--- /dev/null
+++ b/test/fixtures/import-sss-css.css
@@ -0,0 +1 @@
+@import "foo-recursive.sss";
diff --git a/test/fixtures/import-sss-css.expected.css b/test/fixtures/import-sss-css.expected.css
new file mode 100644
index 00000000..333f411a
--- /dev/null
+++ b/test/fixtures/import-sss-css.expected.css
@@ -0,0 +1,5 @@
+bar{}
+
+foo.recursive{
+  color: red
+}
diff --git a/test/fixtures/import-sss.css b/test/fixtures/import-sss.css
new file mode 100644
index 00000000..52e99911
--- /dev/null
+++ b/test/fixtures/import-sss.css
@@ -0,0 +1 @@
+@import "sugarbar.sss";
diff --git a/test/fixtures/import-sss.expected.css b/test/fixtures/import-sss.expected.css
new file mode 100644
index 00000000..f9db5d72
--- /dev/null
+++ b/test/fixtures/import-sss.expected.css
@@ -0,0 +1,3 @@
+.sugarbar {
+  color: blue
+}
diff --git a/test/fixtures/imports/foo-recursive.sss b/test/fixtures/imports/foo-recursive.sss
new file mode 100644
index 00000000..0e24a764
--- /dev/null
+++ b/test/fixtures/imports/foo-recursive.sss
@@ -0,0 +1,4 @@
+@import "bar.css"
+
+foo.recursive
+  color: red
diff --git a/test/fixtures/imports/import-sugarbar.css b/test/fixtures/imports/import-sugarbar.css
new file mode 100644
index 00000000..32cbada9
--- /dev/null
+++ b/test/fixtures/imports/import-sugarbar.css
@@ -0,0 +1,3 @@
+@import "sugarbar.sss";
+
+import.sugarbar{}
diff --git a/test/fixtures/imports/sugarbar.sss b/test/fixtures/imports/sugarbar.sss
new file mode 100644
index 00000000..602386df
--- /dev/null
+++ b/test/fixtures/imports/sugarbar.sss
@@ -0,0 +1,2 @@
+.sugarbar
+  color: blue
diff --git a/test/fixtures/sugar-import-css.expected.css b/test/fixtures/sugar-import-css.expected.css
new file mode 100644
index 00000000..20df4744
--- /dev/null
+++ b/test/fixtures/sugar-import-css.expected.css
@@ -0,0 +1,4 @@
+bar{}
+.sugar{
+  color: white
+}
diff --git a/test/fixtures/sugar-import-css.sss b/test/fixtures/sugar-import-css.sss
new file mode 100644
index 00000000..e9d794f5
--- /dev/null
+++ b/test/fixtures/sugar-import-css.sss
@@ -0,0 +1,3 @@
+@import "bar.css"
+.sugar
+  color: white
diff --git a/test/fixtures/sugar.expected.css b/test/fixtures/sugar.expected.css
new file mode 100644
index 00000000..1e6583a1
--- /dev/null
+++ b/test/fixtures/sugar.expected.css
@@ -0,0 +1,6 @@
+.sugarbar {
+  color: blue
+}
+.sugar {
+  color: white
+}
diff --git a/test/fixtures/sugar.sss b/test/fixtures/sugar.sss
new file mode 100644
index 00000000..58815ae3
--- /dev/null
+++ b/test/fixtures/sugar.sss
@@ -0,0 +1,3 @@
+@import "sugarbar.sss"
+.sugar
+  color: white
diff --git a/test/fixtures/transform-content.css b/test/fixtures/transform-content.css
deleted file mode 100644
index 0a2e522a..00000000
--- a/test/fixtures/transform-content.css
+++ /dev/null
@@ -1 +0,0 @@
-@import "foo"
diff --git a/test/fixtures/transform-content.expected.css b/test/fixtures/transform-content.expected.css
deleted file mode 100644
index 44fe46f6..00000000
--- a/test/fixtures/transform-content.expected.css
+++ /dev/null
@@ -1 +0,0 @@
-transformed-content {}
diff --git a/test/fixtures/transform-undefined.css b/test/fixtures/transform-undefined.css
deleted file mode 100644
index 0a2e522a..00000000
--- a/test/fixtures/transform-undefined.css
+++ /dev/null
@@ -1 +0,0 @@
-@import "foo"
diff --git a/test/fixtures/transform-undefined.expected.css b/test/fixtures/transform-undefined.expected.css
deleted file mode 100644
index d2d19a3e..00000000
--- a/test/fixtures/transform-undefined.expected.css
+++ /dev/null
@@ -1 +0,0 @@
-foo{}
diff --git a/test/helpers/compare-fixtures-ext.js b/test/helpers/compare-fixtures-ext.js
new file mode 100644
index 00000000..de9a4291
--- /dev/null
+++ b/test/helpers/compare-fixtures-ext.js
@@ -0,0 +1,32 @@
+var fs = require("fs")
+var postcss = require("postcss")
+var assign = require("object-assign")
+var atImport = require("../..")
+
+function read(name, ext) {
+  if (!ext) ext = ".css"
+  return fs.readFileSync("fixtures/" + name + ext, "utf8")
+}
+
+module.exports = function(t, name, ext, opts, postcssOpts, warnings) {
+  opts = assign({ path: "fixtures/imports" }, opts)
+  return postcss(atImport(opts))
+    .process(read(name, ext), postcssOpts || {})
+    .then(function(result) {
+      var actual = result.css
+      var expected = read(name + ".expected")
+      // handy thing: checkout actual in the *.actual.css file
+      fs.writeFile("fixtures/" + name + ".actual.css", actual)
+      t.is(actual, expected)
+      if (!warnings) {
+        warnings = []
+      }
+      result.warnings().forEach(function(warning, index) {
+        t.is(
+          warning.text,
+          warnings[index],
+          "unexpected warning: \"" + warning.text + "\""
+        )
+      })
+    })
+}
diff --git a/test/import-events.js b/test/import-events.js
index 42468a2e..c6f6dbb7 100644
--- a/test/import-events.js
+++ b/test/import-events.js
@@ -25,34 +25,6 @@ test("should have a callback that returns an object" +
     })
 })
 
-test("should have a callback shortcut for webpack", t => {
-  var files = []
-  var webpackMock = {
-    addDependency: file => {
-      files.push(file)
-    },
-  }
-
-  return postcss()
-    .use(atImport({
-      path: "fixtures/imports",
-      addDependencyTo: webpackMock,
-    }))
-    .process(readFileSync("fixtures/media-import.css"), {
-      from: "fixtures/media-import.css",
-    })
-    .then(() => {
-      t.deepEqual(
-        files,
-        [
-          resolve("fixtures/media-import.css"),
-          resolve("fixtures/imports/media-import-level-2.css"),
-          resolve("fixtures/imports/media-import-level-3.css"),
-        ]
-      )
-    })
-})
-
 test("should add dependency message for each import", t => {
   return postcss()
     .use(atImport({
diff --git a/test/import.js b/test/import.js
index 857ae69a..1c07717b 100644
--- a/test/import.js
+++ b/test/import.js
@@ -47,18 +47,14 @@ test("should not fail with absolute and local import", t => {
     })
 })
 
-test("should output readable trace", t => {
+test("should error when file not found", t => {
+  t.plan(1)
   var file = "fixtures/imports/import-missing.css"
   return postcss()
     .use(atImport())
     .process(readFileSync(file), { from: file })
-    .then(result => {
-      t.is(
-        result.warnings()[0].text,
-        /* eslint-disable max-len */
-        "Failed to find 'missing-file.css'\n    in [ \n        " + path.resolve("fixtures/imports") + "\n    ]"
-        /* eslint-enabme max-len */
-      )
+    .catch(err => {
+      t.truthy(err)
     })
 })
 
diff --git a/test/plugins.js b/test/plugins.js
index 040bdc69..55dea662 100644
--- a/test/plugins.js
+++ b/test/plugins.js
@@ -1,6 +1,5 @@
 import test from "ava"
 import postcss from "postcss"
-import scss from "postcss-scss"
 import atImport from ".."
 import compareFixtures from "./helpers/compare-fixtures"
 
@@ -51,15 +50,3 @@ test("should remain silent when value is an empty array", () => {
     }))
     .process("")
 })
-
-test("should process custom syntax", t => {
-  return compareFixtures(t, "scss-syntax", null, {
-    syntax: scss,
-  })
-})
-
-test("should process custom syntax by parser", t => {
-  return compareFixtures(t, "scss-parser", null, {
-    parser: scss,
-  })
-})
diff --git a/test/transform.js b/test/transform.js
deleted file mode 100644
index 5db74405..00000000
--- a/test/transform.js
+++ /dev/null
@@ -1,26 +0,0 @@
-import test from "ava"
-import compareFixtures from "./helpers/compare-fixtures"
-
-test.serial("should accept content", t => {
-  return compareFixtures(t, "transform-content", {
-    transform: () => "transformed-content {}",
-  })
-})
-
-test.serial("should accept promised content", t => {
-  return compareFixtures(t, "transform-content", {
-    transform: () => Promise.resolve("transformed-content {}"),
-  })
-})
-
-test.serial("should ignore returned undefined", t => {
-  return compareFixtures(t, "transform-undefined", {
-    transform: () => undefined,
-  })
-})
-
-test.serial("should ignore promised undefined", t => {
-  return compareFixtures(t, "transform-undefined", {
-    transform: () => Promise.resolve(undefined),
-  })
-})