diff --git a/package.json b/package.json
index 6ece481..f6e5c42 100644
--- a/package.json
+++ b/package.json
@@ -19,7 +19,7 @@
   "dependencies": {
     "lodash": "^4.15.0",
     "prop-types": "^15.6.0",
-    "simple-markdown": "^0.3.1"
+    "simple-markdown": "1.0.0-alpha.0"
   },
   "peerDependencies": {
     "react": "*",
diff --git a/src/index.js b/src/index.js
index f3f16bb..f518fe4 100644
--- a/src/index.js
+++ b/src/index.js
@@ -68,7 +68,7 @@ class Markdown extends Component<Props> {
       const tree = SimpleMarkdown.parserFor(rules)(blockSource, {
         inline: false,
       })
-      return SimpleMarkdown.reactFor(SimpleMarkdown.ruleOutput(rules, 'react'))(
+      return SimpleMarkdown.outputFor(rules, 'react')(
         tree,
       )
     }
diff --git a/src/rules.js b/src/rules.js
index 5514704..26ba03c 100644
--- a/src/rules.js
+++ b/src/rules.js
@@ -96,7 +96,7 @@ export default styles => ({
     react: (node, output, parentState) => {
       const state = { ...parentState }
       state.withinText = true
-      const stylesToApply = [styles.heading, styles[`heading ${node.level}`]]
+      const stylesToApply = [styles.heading, styles[`heading${node.level}`]]
       state.stylesToApply = stylesToApply
       return createElement(
         Text,
diff --git a/yarn.lock b/yarn.lock
index d5d37a7..69da5fe 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -2688,9 +2688,9 @@ signal-exit@^3.0.0, signal-exit@^3.0.2:
   version "3.0.2"
   resolved "https://registry.yarnpkg.com/signal-exit/-/signal-exit-3.0.2.tgz#b5fdc08f1287ea1178628e415e25132b73646c6d"
 
-simple-markdown@^0.3.1:
-  version "0.3.2"
-  resolved "https://registry.yarnpkg.com/simple-markdown/-/simple-markdown-0.3.2.tgz#eb3902dc3bcf74fdfc1883230286dcadea870dc0"
+simple-markdown@0.4.0:
+  version "0.4.0"
+  resolved "https://registry.yarnpkg.com/simple-markdown/-/simple-markdown-0.4.0.tgz#86ec1344c7747a3ca120f5e4325be88cb4a67cc3"
 
 slash@^1.0.0:
   version "1.0.0"