diff --git a/README.md b/README.md
index feb8c9c8..42cc457a 100644
--- a/README.md
+++ b/README.md
@@ -61,6 +61,11 @@ module.exports = {
       Hello World!
     </Button>
   `,
+  customStyles: `
+    pre.CodeMirror-line {
+			font-size: 15px;
+		}
+  `,
   webpackConfig: () => ({
     // Custom webpack config goes here...
   })
diff --git a/src/index.js b/src/index.js
index 7acc579c..e0e95b6e 100644
--- a/src/index.js
+++ b/src/index.js
@@ -14,6 +14,15 @@ const widths = playroomConfig.widths || [320, 375, 768, 1024];
 const outlet = document.createElement('div');
 document.body.appendChild(outlet);
 
+if (typeof playroomConfig.customStyles === 'string') {
+  const customStyles = document.createElement('style');
+  document.head.appendChild(customStyles);
+  customStyles.type = 'text/css';
+  customStyles.appendChild(
+    document.createTextNode(playroomConfig.customStyles)
+  );
+}
+
 export const store = localforage.createInstance({
   name: playroomConfig.storageKey,
   version: 1