diff --git a/src/slide.js b/src/slide.js
index 304d53f..a45cbe2 100644
--- a/src/slide.js
+++ b/src/slide.js
@@ -2,7 +2,7 @@ import React from "react";
 import animation from "./animation";
 import theme from "./nightOwl";
 
-const themeStylesByType = {};
+const themeStylesByType = Object.create(null);
 theme.styles.forEach(({ types, style }) => {
   types.forEach(type => {
     themeStylesByType[type] = Object.assign(
diff --git a/src/tokenizer.js b/src/tokenizer.js
index a53aa45..681445b 100644
--- a/src/tokenizer.js
+++ b/src/tokenizer.js
@@ -19,14 +19,14 @@ function flattenTokens(tokens) {
 }
 
 // Convert strings to tokens
-function tokenizeStrings(prismTokens) {
+function tokenizeStrings(prismTokens, parentType = "plain") {
   return prismTokens.map(pt =>
     typeof pt === "string"
-      ? { type: "plain", content: pt }
+      ? { type: parentType, content: pt }
       : {
           type: pt.type,
           content: Array.isArray(pt.content)
-            ? tokenizeStrings(pt.content)
+            ? tokenizeStrings(pt.content, pt.type)
             : pt.content
         }
   );