diff --git a/CHANGELOG.md b/CHANGELOG.md
index 54434fa..532f50a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,17 @@
 # Changelog
 
+## 0.8.4
+
+_2019-12-05_
+
+Fixed bug with function helpers where empty string would be passed as first arg when no args were passed, causing default args not to work:
+
+```js
+z.helper({ test: (x = 5) => `margin ${x}` })
+
+z`test` // this would result in no style being applied, since x would be '' instead of defaulting to 5
+```
+
 ## 0.8.3
 
 _2019-11-12_
diff --git a/package-lock.json b/package-lock.json
index aa3d8be..94fce2e 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,6 +1,6 @@
 {
   "name": "zaftig",
-  "version": "0.8.3",
+  "version": "0.8.4",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {
@@ -941,9 +941,9 @@
       "dev": true
     },
     "terser": {
-      "version": "4.4.0",
-      "resolved": "https://registry.npmjs.org/terser/-/terser-4.4.0.tgz",
-      "integrity": "sha512-oDG16n2WKm27JO8h4y/w3iqBGAOSCtq7k8dRmrn4Wf9NouL0b2WpMHGChFGZq4nFAQy1FsNJrVQHfurXOSTmOA==",
+      "version": "4.4.2",
+      "resolved": "https://registry.npmjs.org/terser/-/terser-4.4.2.tgz",
+      "integrity": "sha512-Uufrsvhj9O1ikwgITGsZ5EZS6qPokUOkCegS7fYOdGTv+OA90vndUbU6PEjr5ePqHfNUbGyMO7xyIZv2MhsALQ==",
       "dev": true,
       "requires": {
         "commander": "^2.20.0",
diff --git a/package.json b/package.json
index 25ca93d..dc0fb84 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "zaftig",
-  "version": "0.8.3",
+  "version": "0.8.4",
   "description": "css for your js",
   "source": "src/index.js",
   "main": "dist/zaftig.es5.min.js",
@@ -28,6 +28,6 @@
     "buble": "^0.19.8",
     "jsdom": "^15.2.1",
     "ospec": "^4.0.1",
-    "terser": "^4.4.0"
+    "terser": "^4.4.2"
   }
 }
diff --git a/src/index.js b/src/index.js
index 43317b7..d768d10 100644
--- a/src/index.js
+++ b/src/index.js
@@ -223,7 +223,7 @@ const makeZ = (conf = {}) => {
   const runHelper = (key, value) => {
     const helper = helpers[key]
     return typeof helper === 'function'
-      ? helper(...(value || '').split(' '))
+      ? helper(...(value ? value.split(' ') : []))
       : helper && helper + ' ' + value
   }
 
diff --git a/test.js b/test.js
index 94011bb..d5944c7 100644
--- a/test.js
+++ b/test.js
@@ -21,8 +21,8 @@ const singleRule = (input, output, z = zaf.new({ id: 'test' })) => {
   o(z.getSheet().sheet.cssRules[0].cssText).equals('.test-1 {' + output + '}')
 }
 
-const fullSheet = str => {
-  const z = zaf.new({ id: 'test', debug: true })
+const fullSheet = (str, conf) => {
+  const z = zaf.new({ ...conf, id: 'test', debug: true })
   const [input, output] = str.split('===')
   const style = z(input)
   o('' + style).equals('.test-1')
@@ -165,5 +165,51 @@ h 200
     o(z.getSheet().sheet.cssRules.length).equals(2)
   })
   o('flex does not generate px', () => o(zaf.style`flex 1`.trim()).equals('flex: 1;'))
+  o('helpers work', () => {
+    const helpers = {
+      'no-arg': 'padding 10',
+      basic: 'margin',
+      'basic-fn': (x = 1, y = 2, z = 3) => `content '${x} ${y} ${z}'`,
+      multi: 'height 50;width 50'
+    }
+    fullSheet(
+      css`
+h1 { basic 5 }
+h2 { basic 5 10 }
+h3 { basic-fn; no-arg; multi }
+h4 { basic-fn hello }
+h5 { basic-fn hello world }
+h6 { basic-fn hello world foo }
+===
+.test-1 h1 {
+  margin: 5px;
+}
+
+.test-1 h2 {
+  margin: 5px 10px;
+}
+
+.test-1 h3 {
+  content: '1 2 3';
+  padding: 10px;
+  height: 50px;
+  width: 50px;
+}
+
+.test-1 h4 {
+  content: 'hello 2 3';
+}
+
+.test-1 h5 {
+  content: 'hello world 3';
+}
+
+.test-1 h6 {
+  content: 'hello world foo';
+}
+    `,
+      { helpers }
+    )
+  })
   // TODO: add tests for selector prefixing and better error handling (JSDOM doesn't seem to give syntax errors like browsers do)
 })